Financial Analysis puzzles, solved step by step
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083A phone sells for Rs 57,000 cash today, or on a 'no-cost EMI' of Rs 10,000 a month for six months, the first instalment due a month from now. What interest rate is hidden in the EMI?Bank creditCorporate FP&A
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Roughly what annual rate is hidden in the EMI?
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About 1.49% a month, or 19.4% a year effective. The real price is the Rs 57,000 cash price, so choosing the EMI means borrowing Rs 57,000 and repaying Rs 60,000 in six monthly instalments. The rate that makes six payments of Rs 10,000 worth exactly Rs 57,000 today is 1.49% a month. The forgone Rs 3,000 discount is the interest, charged on a balance that shrinks every month.
Where is the interest, if the EMI says no-cost?
A friend offers to sell you his bike for Rs 57,000 today, or for Rs 60,000 paid over six months. Nobody calls the second option interest-free; it is a loan of Rs 57,000 with Rs 3,000 of interest. A shop doing the same thing is no different. When a cash discount is available, the discount you give up by paying in instalments is the interest on the loan. The 'no-cost' label means the instalments add up to the sticker price, not that money has no time value.
So the question becomes: at what monthly rate is a stream of six Rs 10,000 payments, starting in one month, worth Rs 57,000 today? That is the internal rate of return of the loan.
The relationshipr the monthly interest rate hidden in the instalments k the month each Rs 10,000 instalment is paid What it says in wordsThe hidden rate is the one that discounts the six instalments back to the cash price.Six Rs 10,000 instalments add to Rs 60,000 at face value, but discounted at 1.49% a month they are worth exactly the Rs 57,000 cash price, so the Rs 3,000 discount given up is interest at 19.4% a year effective. How do you solve it without a spreadsheet?
Guess and check. The annuity factor must be 57,000 / 10,000 = 5.70. At 1% a month, six payments are worth 5.80 times one payment; at 2% they are worth 5.60. Halfway gives about 1.5%, and 1.5% gives 5.697, a whisker under 5.70, so the answer is just below: 1.49%. Then compound, do not multiply: 1.0149 to the power 12 is 1.194, so the effective annual rate is 19.4%, against 17.8% if you simply multiply by 12.
A second check uses the average balance. The loan starts at Rs 57,000 and is paid down to zero over six months; the balance at the start of each month averages about Rs 33,700. Rs 3,000 of interest on about Rs 33,700 over six months is 8.9%, or about 17.8% a year simple, which matches 1.49% x 12.
What changes the answer in real life?
Timing matters a great deal. If the first instalment is due today rather than in a month, you really borrow only Rs 47,000 and repay Rs 50,000 over five months, and the hidden rate jumps to 2.10% a month, about 28% a year. Any processing fee, or tax charged on the interest component, raises the true cost further, so always ask what you pay on day one. Check the specific charges and the current tax treatment with the lender. And if there was never a cash discount to forgo, the EMI really is close to free for the buyer, because the retailer, not the buyer, is paying the lender.
Where candidates lose it
The quick wrong answer is about 5%: Rs 3,000 on Rs 57,000. Some candidates double it to 10.5% for a year and feel careful. Both ignore that the loan is repaid monthly, so the average balance is only a little over half of Rs 57,000, and the rate on what is actually owed is far higher than the headline.
The second loss is multiplying the monthly rate by 12 and calling it the annual rate. 17.8% is a nominal rate; money compounding monthly at 1.49% grows 19.4% in a year. Give both and name which is which.
What the interviewer asks next
- If the first instalment is paid at purchase, what is the hidden rate? (About 2.1% a month.)
- The cash discount is only Rs 1,000. What is the hidden rate now, roughly?
- Who pays the lender when the retailer offers no cash discount at all, and why would the retailer do that?
085A company writes off Rs 20 crore of obsolete inventory in full, at a 25% tax rate. Walk the three statements. Then, next year, the same stock is sold for scrap at Rs 5 crore: what happens to that year's gross margin, and why?Big FourCorporate FP&A
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In the year of the write-down, what happens to cash from operations?
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Year one: profit falls Rs 15 crore, inventory falls Rs 20 crore, cash rises Rs 5 crore from tax saved. Year two: gross margin is flattered. The scrapped stock sits on the books at zero, so the Rs 5 crore sale is pure gross profit, lifting margin from 30.0% to 30.9% on these figures. The write-down moved profit between years, because it wrote off more than the stock turned out to be worth.
How does a write-down move through the three statements?
Suppose you bought Rs 20,000 of winter jackets for your shop two years ago, and they are now unsellable. Admitting it does not take any money out of your till today; the money left when you bought them. An inventory write-down is a non-cash expense that recognises a loss of value already suffered, so its only cash effect is the tax it saves.
Statement Line Year 1, Rs crore Income statement Cost of goods sold (write-down) +20.0 Income statement Tax at 25% -5.0 Income statement Net income -15.0 Cash flow Net income -15.0 Cash flow Add back non-cash write-down +20.0 Cash flow Cash from operations +5.0 Balance sheet Inventory -20.0 Balance sheet Cash +5.0 Balance sheet Retained earnings -15.0 Year one: assets fall Rs 15 crore (inventory -20, cash +5) and equity falls Rs 15 crore, so the balance sheet balances. Assumes the write-down is tax deductible when booked; confirm the rule in your jurisdiction. Check the balance sheet: assets are down Rs 15 crore, Rs 20 crore of stock gone and Rs 5 crore of cash added, and retained earnings are down by the same Rs 15 crore. It balances, which is the test an interviewer listens for.
Why does next year's gross margin look better than normal?
The stock now has a book value of zero. When it is sold for Rs 5 crore, revenue rises Rs 5 crore and cost of goods sold rises by nothing, because there is no cost left to expense. On a normal Rs 400 crore of sales at 30%, the write-down year shows 25.0% and the scrap year 30.9%. Writing down more than the stock is finally worth pulls a loss into this year and pushes an equal gain into the next.
Gross margin drops to 25.0% in the write-down year and rises to 30.9% when the zero-value stock sells for scrap, while across both years profit after tax totals minus Rs 11.25 crore, exactly the true loss after tax. Over both years nothing is lost or gained by the timing. Pre-tax, the total is minus Rs 20 crore plus Rs 5 crore, or minus Rs 15 crore: the true economic loss on stock that cost Rs 20 crore and fetched Rs 5 crore. Accounting rules generally require inventory to be carried at the lower of cost and net realisable value. If the company expected Rs 5 crore of scrap value, the honest write-down was Rs 15 crore, and the sale would have produced no gain at all.
What does an analyst do with this?
Treat both effects as one event. Strip the write-down out of year one's gross margin and the scrap gain out of year two's, and you see the business's real run-rate margin of 30%. A large write-down followed by margins above the old normal is a pattern worth asking management about, because over-provisioning creates a reserve that can be released into later profits. That is not proof of anything; obsolete stock genuinely varies in what it fetches. It is a question to ask.
Where candidates lose it
The common error is saying cash falls by Rs 20 crore, or by Rs 15 crore, in the write-down year. The cash left when the stock was bought. The write-down is added back on the cash flow statement, and the only cash effect is the Rs 5 crore of tax saved.
The second loss is missing the follow-on. Candidates walk year one cleanly and then say the scrap sale is 'just revenue'. It is revenue with no cost attached, because the cost was already expensed, and that is why the margin jumps. Connecting the two years is the point of the question.
What the interviewer asks next
- How would the answer change if the tax authority allowed the deduction only when the stock is actually disposed of?
- Where in the accounts would you look to see how large the inventory provision is and how it moved?
- Walk the three statements if instead the stock is sold for Rs 25 crore.
087You lend to 10 borrowers. Each has a 2% chance of defaulting over the year, independently of the others. What is the chance that at least one defaults, and what is the expected number of defaults?Rating agenciesBank credit
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What is the chance that at least one of the ten defaults?
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The chance of at least one default is 18.3%, and the expected number of defaults is 0.2. Work from the complement: each loan survives with probability 98%, so all ten survive with probability 0.98^10 = 81.7%, and at least one default is the rest. The expected number is simply 10 x 2% = 0.2, which holds whether or not the loans are independent. Independence matters for the first answer, not the second.
Why work from the chance that nothing happens?
Ask what the chance is that at least one of ten friends is late for dinner, each being late one time in fifty. Counting the ways someone could be late is messy: one late, two late, any combination. Counting the single way nobody is late is easy: everyone on time. 'At least one' is one minus 'none', and 'none' for independent events is just the single probabilities multiplied. Each loan survives with probability 0.98, so all ten survive with probability 0.98^10.
To do 0.98^10 in your head, use the shortcut that (1 minus x) to the power n is close to 1 minus nx plus a correction of n(n minus 1)/2 times x squared: 1 minus 0.20 plus 45 x 0.0004 = 0.818. The exact figure is 0.8171, so the chance of at least one default is 18.29%. A second check is the Poisson shortcut, 1 minus e to the minus 0.2, which gives 18.1%.
With ten independent loans each carrying a 2% default chance, no default happens 81.7% of the time, so at least one default happens 18.3% of the time, while expected defaults are 0.2 whether the loans are independent or perfectly linked. Why is the expected number so much simpler?
Expected values add, always. Each loan contributes 0.02 expected defaults, and ten loans contribute 0.2. The expected number of defaults is 0.2 regardless of how the loans are connected, because the expectation of a sum is the sum of the expectations even when the events are correlated. The distribution behind it is lopsided: 81.7% of the time nothing happens, 16.7% of the time exactly one loan fails, and two or more fail 1.6% of the time.
What does correlation change?
Take the extreme. If all ten borrowers are suppliers to one factory and fail together or survive together, there is a 2% chance that all ten default and a 98% chance that none does. Expected defaults are still 0.2. But the chance of at least one default falls to 2%, and the chance of losing the entire book jumps from practically zero to 2%. Correlation does not change the average loss; it moves probability from many small losses into rare large ones, which is the loss a lender cannot survive. That is why credit portfolio work spends its effort on concentration and correlation rather than on the average default rate, and why a portfolio of ten loans to one industry is riskier than its expected loss suggests.
Where candidates lose it
The fast wrong answer is 20%: ten loans times 2%. Adding probabilities only works for events that cannot happen together, and two loans can both default. The error is small here, 20% against 18.3%, but it grows quickly: with 100 such loans the same method gives 200%, which is impossible.
The second loss is giving 18.3% and stopping. The question says independently for a reason. Saying what correlation would do, same expected defaults, fatter tail, is the part a credit interviewer is listening for.
What the interviewer asks next
- How many such loans do you need before at least one default is more likely than not?
- If each loan is Rs 10 crore and recovers 40% on default, what is the expected loss on the book?
- Two of the ten borrowers are in the same group of companies. Does the chance of at least one default go up or down?
088A distributor's inventory rose 20% in rupees over the year, yet its inventory days fell from 60 to 50. What must have happened to cost of goods sold?Corporate FP&ACost accounting
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By how much must cost of goods sold have grown?
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Cost of goods sold must have grown about 44%. Inventory days are inventory divided by daily cost of goods sold. For days to fall by a sixth while inventory rises a fifth, the denominator must grow by 1.2 x 60 / 50 = 1.44 times. So the larger stock is serving a much larger business, and is leaner relative to it. Had days stayed at 60, the distributor would be holding Rs 28.8 crore more stock in this example.
How can a bigger stock be leaner?
A kirana shop keeps Rs 60,000 of stock and sells Rs 1,000 a day at cost: two months of cover. A year later it keeps Rs 72,000 and sells Rs 1,440 a day: fifty days of cover. The shelf is fuller, yet each rupee of stock waits less time to be sold. Inventory days measure how long stock waits, not how much there is, so a larger rupee stock can still be leaner if what it serves grew faster.
The relationshipInventory the stock held at the balance sheet date COGS cost of goods sold over the year Days inventory days, how long the stock would last at the current rate of sale What it says in wordsThe growth in cost of goods sold equals the growth in inventory times the ratio of old days to new days.Put rupees on it. Last year: COGS of Rs 730 crore is Rs 2.0 crore a day, and Rs 120 crore of stock is 60 days of it. This year inventory is Rs 144 crore. For that to be 50 days, daily COGS must be Rs 2.88 crore, an annual Rs 1,051.2 crore, up 44%.
Inventory grew 20% while cost of goods sold grew 44%, so stock fell from 60 to 50 days of cover, and at the old 60 days the distributor would hold Rs 28.8 crore more inventory. What is the cash meaning of the change?
Compare the stock with what it would have been at the old turn. At 60 days, this year's cost of goods sold would need Rs 172.8 crore of inventory. The distributor holds Rs 144 crore. The faster turn means Rs 28.8 crore less cash tied up in stock than the business would otherwise need, even though the balance sheet shows inventory up Rs 24 crore. An analyst who reads only the rupee change calls this a working capital problem; the ratio says it is a working capital improvement.
What would make you distrust the 50 days?
Three checks. Year-end timing: inventory is a snapshot, and a stock-light last week of March can flatter the ratio; average inventory over the year is a better numerator. The denominator: some analysts compute days on revenue, not COGS, and mixing the two across years breaks the comparison. And mix: if the growth came from a fast-moving new product line, the old lines may be turning as slowly as ever. The ratio summarises; it does not explain.
Where candidates lose it
The common slip is adding instead of multiplying: inventory up 20%, days down about 17%, so COGS up about 37%. Ratios combine through their growth factors, 1.2 times 1.2, which gives 44%. The additive shortcut drifts further the bigger the moves.
The second loss is reading the rupee rise in inventory as bad news. The question is built to see whether you look past the level to the rate: more stock, held for less time, against much higher sales. Say what cash the faster turn saved.
What the interviewer asks next
- Inventory fell 10% while days rose from 45 to 60. What happened to cost of goods sold?
- Why might average inventory give a different answer from closing inventory here?
- How would you split the change in inventory into a part from growth and a part from efficiency?
089A company's revenue is Rs 1,000 crore in both years. Its EBITDA margin rises from 18% to 20%, while its EBIT margin falls from 12% to 11%. What must have happened to depreciation and amortisation, in rupees, and what could explain it?Corporate FP&AEquity research
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By how much did depreciation and amortisation change?
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Depreciation and amortisation rose from Rs 60 crore to Rs 90 crore, up Rs 30 crore or half again. D&A is exactly the gap between EBITDA and EBIT: 180 minus 120 last year, 200 minus 110 this year. The usual causes are a burst of capex now being depreciated, an acquisition bringing amortisation of intangibles, or an accounting change, such as lease accounting, that moves a cash cost out of operating expenses and into depreciation.
How do you find D&A from two margins?
If your take-home pay rises but your savings fall, something between the two lines got bigger: rent, EMI, school fees. You find it by looking at the gap, not the lines. EBITDA and EBIT differ by exactly one thing, depreciation and amortisation, so when the two margins move in opposite directions, D&A has grown by the sum of the two moves. Here, 2 points up and 1 point down is 3 points of Rs 1,000 crore of revenue, or Rs 30 crore.
Convert to rupees to be sure. EBITDA is Rs 180 crore last year and Rs 200 crore this year; EBIT is Rs 120 crore and Rs 110 crore. D&A is Rs 60 crore, then Rs 90 crore. Revenue is flat, so D&A went from 6% to 9% of revenue.
On flat revenue of Rs 1,000 crore, EBITDA rose Rs 20 crore while EBIT fell Rs 10 crore, so depreciation and amortisation must have risen Rs 30 crore, from Rs 60 crore to Rs 90 crore. What could explain a 50% jump in D&A on flat revenue?
Three stories, each with a different meaning. First, a capex burst: a new plant or system has come into use and is being depreciated, but has not yet lifted revenue. That is a timing story, and the question is when revenue arrives. Second, an acquisition: buying a business brings customer lists and brands onto the balance sheet, and amortising them raises D&A without any new cash spend. Third, an accounting change. Under lease accounting standards such as Ind AS 116, rent stops being an operating expense and becomes depreciation plus interest, which raises EBITDA and D&A together without changing the cash the company pays.
The lease story fits the EBITDA rise neatly, since rent leaving operating expenses lifts EBITDA directly. But EBIT usually edges up under that change too, because part of the old rent now sits in interest, below EBIT. EBIT falling here suggests at least some genuine new depreciation as well.
Which margin should an analyst trust?
Neither on its own. EBITDA ignores the cost of the assets that produce the profit, so a company can raise its EBITDA margin simply by buying capacity or by reclassifying rent. EBIT charges for those assets, but through accounting depreciation that may not match their real wear. The honest check is cash: EBITDA less capex less lease payments, compared across both years, tells you whether the business really earns more. Ask management which of the three stories is true before praising the higher EBITDA margin.
Where candidates lose it
The common slip is subtracting the margin changes: 2 points minus 1 point, so D&A rose 1 point, Rs 10 crore. The moves go in opposite directions, so the gap widened by both: 3 points, Rs 30 crore. Working in rupees removes the confusion at once.
The second loss is giving the number without a reason. The interviewer wants a cause, and the strong answer names more than one, capex, acquisition amortisation and lease accounting, and says what each would mean for the cash the business really generates.
What the interviewer asks next
- If the change came entirely from lease accounting, what would you expect to see in interest expense?
- Revenue grew 10% and both margins stayed flat. What happened to D&A in rupees?
- Why do lenders often look at EBITDA less capex rather than EBITDA?
090A company has net income of Rs 300 crore and 10 crore shares. It also has Rs 500 crore of 6% convertible bonds, convertible at Rs 250 a share. The tax rate is 25%. What is basic EPS, what is diluted EPS on the if-converted method, and what happens to each statement if the bonds actually convert?Equity researchBig Four
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How many new shares does conversion create?
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Basic EPS is Rs 30.0; diluted EPS is Rs 26.88, about 10% lower. The if-converted method assumes conversion: add back the after-tax interest saved, Rs 30 crore x 0.75 = Rs 22.5 crore, and add 2 crore shares. That gives Rs 322.5 crore over 12 crore shares. On actual conversion, debt falls Rs 500 crore and equity rises Rs 500 crore, interest expense stops, and no cash changes hands.
What does the if-converted method assume?
Imagine a friend lent your shop Rs 5 lakh and can choose, any time, to swap the loan for a share of the business. To be honest with your other partners about what each share is worth, you would show the numbers as if the friend has already swapped: no more interest to pay, but one more partner splitting the profit. Diluted EPS shows earnings per share as if every convertible security that would reduce EPS had already converted, adding back the interest it would save and adding the shares it would create.
The interest is Rs 500 crore x 6% = Rs 30 crore a year. It was tax-deductible, so removing it raises net income by only Rs 30 crore x (1 minus 25%) = Rs 22.5 crore. Conversion creates Rs 500 crore / Rs 250 = 2 crore shares. Diluted EPS is (300 + 22.5) / (10 + 2) = Rs 26.875, which rounds to Rs 26.88.
The relationshipNI net income, Rs 300 crore I annual interest on the convertible, Rs 30 crore N existing shares, 10 crore F / P_c face value over conversion price, the new shares What it says in wordsAdd the after-tax interest saved to earnings and the conversion shares to the share count.Conversion lifts earnings by 7.5% but the share count by 20%, because each new share brings only Rs 11.25 of saved after-tax interest against Rs 30 earned by each existing share, so diluted EPS falls to Rs 26.88. How do you know whether a convertible dilutes?
Compare what each new share brings with what each existing share earns. Each conversion share brings Rs 22.5 crore / 2 crore = Rs 11.25 of earnings, far below basic EPS of Rs 30, so including the convertible lowers EPS and it must be counted. If basic EPS were below Rs 11.25, conversion would raise EPS; that security is anti-dilutive and is left out of diluted EPS. The test is per security, so a company with several convertibles ranks them from most to least dilutive.
What happens to each statement on actual conversion?
Balance sheet: borrowings fall Rs 500 crore and equity rises Rs 500 crore, split between share capital at face value and securities premium. Total assets do not move; the right-hand side changes its mix and leverage falls sharply. Income statement: from the conversion date, the Rs 30 crore of interest stops, so profit rises Rs 22.5 crore after tax. Cash flow statement: nothing at conversion, because no cash changes hands; it is disclosed as a non-cash transaction. Afterwards, the Rs 30 crore of cash interest is no longer paid. Reported basic EPS after conversion should land close to the diluted EPS already shown, which is why analysts value on the diluted figure.
Where candidates lose it
The common error is adding the full Rs 30 crore of interest back to earnings. Interest was tax-deductible, so saving it also loses the tax shield: only Rs 22.5 crore reaches net income. Using Rs 30 crore gives Rs 27.50 instead of Rs 26.88.
The second loss is the statement walk. Candidates say cash falls by Rs 500 crore to repay the bond, but conversion repays nothing in cash: the bondholders take shares instead. Debt becomes equity, the balance sheet total stays put, and the cash flow statement shows nothing on the day.
What the interviewer asks next
- At what level of net income would this convertible become anti-dilutive?
- The company also has options on 1 crore shares at Rs 200, and the share price is Rs 300. How do they enter diluted EPS?
- Why might a company prefer issuing a convertible to straight debt, and what does it give up?
091A shop offers 20% off, and then an extra 10% off at the till. Is that the same as 30% off? And what discount per unit is 'buy two, get one free'?Corporate FP&ABusiness finance
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On a Rs 1,000 item, what do you pay after 20% off and then a further 10% off?
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No: 20% then 10% off is 28% off, not 30%; buy two get one free is a 33.3% discount per unit. Successive discounts multiply, because the second applies to the already reduced price: 0.80 x 0.90 = 0.72, so you pay 72% of the original. Buy two get one free means paying for two units and taking three, so each unit costs two thirds of its price, a third off, but only if you wanted three.
Why do discounts not simply add?
A Rs 1,000 kurta at 20% off costs Rs 800. The cashier then takes 10% off what you are about to pay, which is Rs 800, so the second discount is worth Rs 80, not Rs 100. You pay Rs 720. Each successive discount is taken off a price that the earlier discounts have already reduced, so discounts combine by multiplying what is left: 0.80 x 0.90 = 0.72, or 28% off. The order does not matter, 10% then 20% also gives 0.72, but the base does.
The relationshipd_1 the first discount, 20% d_2 the second discount, 10% d_total the single discount with the same effect What it says in wordsMultiply what each discount leaves you paying; the total discount is one minus that product.The shortfall from simple addition is the product of the two discounts: 20% x 10% = 2 points, the discount on the discount. It is small here and grows with the size of the cuts: 50% then 50% off is 75% off, not 100%.
On a Rs 1,000 item, 20% then 10% off leaves Rs 720, a 28% discount, against Rs 700 at a flat 30%, while buy two get one free cuts the price per unit by a third, the largest of the offers if you wanted three units. What is buy two, get one free really worth?
You pay for two units and walk out with three, so each unit costs two thirds of the list price. Buy two get one free is a 33.3% discount per unit, deeper than the flat 30%, but only on the condition that you buy three. Buy one, get the second at half price is milder: one and a half prices for two units, 25% off each. If you needed only one, the effective discount of either offer is zero.
Where does this show up at work?
Everywhere rates are applied one after another. A distributor margin taken on a price that already carries a retailer margin, a trade discount followed by a cash discount, a fee charged after another fee: all compound. An FP&A analyst who adds layered discounts to estimate net price will overstate the discount and understate revenue per unit. The same arithmetic runs in reverse for mark-ups: a 20% price rise followed by a 20% cut leaves you 4% below where you started, because 1.2 x 0.8 = 0.96.
Where candidates lose it
The trap is answering yes, 30%, because the two numbers add neatly. The interviewer wants to hear that the second discount works on a smaller base, and the clean proof is 0.8 x 0.9 = 0.72.
The second loss is calling buy two get one free a 50% discount, because one item in two is free. It is one item in three. Count the units you walk out with, not the units you pay for, and add that the offer is only worth anything if you wanted three.
What the interviewer asks next
- A price rises 25% and then falls 20%. Where does it end up?
- What single discount equals 10%, then 10%, then 10% off?
- A distributor buys at 30% below MRP and the retailer at 20% below MRP. What margin, on its own selling price, does the distributor earn?
093A perpetuity pays Rs 100 a year forever, discounted at 10%. What share of its present value comes from the first 10 years of payments? From the first 30?Equity researchCorporate finance
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Roughly what share of the value comes from the first 10 years?
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About 61% from the first 10 years and 94% from the first 30. The perpetuity is worth Rs 100 / 0.10 = Rs 1,000. Payments beyond year N are themselves a perpetuity, starting later, so their share is 1/1.1^N: 38.6% beyond year 10 and 5.7% beyond year 30. Add growth and the far years matter much more: at 5% growth only 37% of the value arrives in the first decade.
Is there a quick way to split a perpetuity by year?
Suppose you are promised a pension of Rs 100 a year forever. Starting ten years from now, what you are owed is again a Rs 100 perpetuity, worth Rs 1,000 at that date; you just have to wait ten years for it. The value of the payments after year N is the full perpetuity value, discounted back N years, so its share of the total is 1/(1 + r)^N and the first N years take the rest. At 10% that is 1/1.1^10 = 0.386 beyond year 10 and 1/1.1^30 = 0.057 beyond year 30.
The relationshipr the discount rate, 10% g the growth rate of the payment, zero here N the number of years counted What it says in wordsThe share of value received in the first N years is one minus the discount factor for N years, adjusted for growth.In rupees, the first ten years are worth Rs 614 of the Rs 1,000. Half the value arrives in the first 7.3 years, because 1.1 to the power 7.3 is 2. A useful mental marker: at 10%, value halves every seven years or so.
Discounted at 10%, a flat perpetuity delivers 61% of its value in the first 10 years and 94% in 30, but if the payment grows 5% a year only 37% arrives in the first decade, which is why a DCF's terminal value dominates. Why does this matter for a DCF?
A DCF forecasts a company for perhaps ten years and puts everything after into a terminal value. With no growth, the terminal value would already be 39% of the total. Companies are usually assumed to grow, and growth pushes value further out: at 5% growth and a 10% discount rate, the gap between them shrinks to about 4.8% a year, half the value arrives only after 14.9 years, and the terminal value is 63% of the total. Most of a DCF's value sits beyond the explicit forecast, so the terminal growth rate and discount rate deserve more scrutiny than the detail of year three.
The limitation runs the other way too. The terminal value depends on the gap between the discount rate and growth, so a small change in either swings it sharply. Present a DCF with the terminal value's share stated and a sensitivity table beside it, rather than a single number.
Where candidates lose it
The intuitive answer is tiny, because ten years is nothing against forever. It ignores discounting: a payment in year 50 is worth under one hundredth of its face value today. The first decade carries 61% of the value with no growth.
The opposite loss comes in the follow-up. Candidates who learn the 61% conclude that the terminal value is a minor detail. Add realistic growth and the far years matter far more: at 5% growth only 37% of the value sits in the first ten years.
What the interviewer asks next
- At what discount rate would the first 10 years carry 75% of a flat perpetuity's value?
- If a DCF's terminal value is 80% of the enterprise value, what does that tell you about where the risk in the valuation sits?
- How does the share change if the discount rate falls from 10% to 8% with 5% growth?
094A cafe sells coffee at Rs 120 a cup, though each cup costs Rs 140 to serve, to bring people in. Each food item earns Rs 60 of contribution. What share of coffee buyers must also buy a food item for the coffee to pay its way?Corporate FP&ACost accounting
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What attach rate makes the coffee break even?
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One coffee buyer in three, 33.3%, must also buy a food item. Each cup loses Rs 20: Rs 140 to serve against Rs 120 of price. Each food item adds Rs 60 of contribution. So one food sale covers the loss on three coffees, and the break-even attach rate is 20 / 60. Two checks matter: only food bought because of the coffee counts, and Rs 140 must be the true extra cost of a cup, not a share of rent.
How do you price a product that loses money on purpose?
A shopkeeper who sells milk below cost does it because people who come in for milk also pick up bread and biscuits. The milk is a door, and its price is justified by what walks through it. A loss leader pays its way when the profit on what customers also buy covers the loss on the leader, so the number to manage is the attach rate. Here, each coffee loses Rs 20 and each food item earns Rs 60.
The relationshipa* the break-even attach rate: share of leader buyers who also buy the add-on contribution price less the variable cost of the add-on What it says in wordsThe break-even attach rate is the loss on the leader divided by the contribution on what it brings in.Three coffees at a Rs 20 loss each balance one food item at Rs 60 of contribution, so the coffee pays its way once one coffee buyer in three also buys food. What makes the one-in-three figure misleading?
Two things. First, only incremental food counts. If half the people buying food would have come in for lunch anyway, their food was not brought in by the cheap coffee, and the coffee cannot claim it. The attach rate that matters is the share of coffee buyers who buy food because they came for coffee, which is lower than the attach rate on the till receipts. Measuring it needs a comparison: a price test in a few outlets, or the behaviour of customers before and after the coffee price changed.
Second, ask what is inside the Rs 140. If it includes a share of rent, staff and the coffee machine, those costs are there whether or not one more cup is sold. Suppose the extra cost of a cup, beans, milk and the cup itself, is Rs 70. Then each coffee contributes Rs 50 at the margin and needs no food to pay its way; it only looks like a loss after fixed costs are spread across it. Decisions about one more sale use contribution; fully loaded cost answers a different question, whether the whole cafe covers its overheads.
What would you track after launch?
Attach rate by time of day, average food contribution per coffee buyer, and the number of new customers the coffee brings in. A cafe that hits 40% attach in the morning and 15% in the afternoon may want the cheap coffee only before noon. The limitation is that habit takes time: a promotion judged on its first two weeks can look worse than it will in month three.
Where candidates lose it
The common slip is setting the attach rate at the point where food covers the full price of the coffee, or dividing the wrong way and getting three food items per coffee. Set the loss per coffee against the gain per food item and it falls out: 20 / 60.
The bigger loss is stopping at a third. The interviewer is waiting for the two questions behind it: is the food sale caused by the coffee, and is Rs 140 really the extra cost of a cup? Either can reverse the conclusion.
What the interviewer asks next
- The cafe raises coffee to Rs 130. What attach rate does it now need?
- Half of the food buyers would have come anyway. What measured attach rate do you need on the till receipts?
- How would you test whether the cheap coffee is bringing in new customers at all?
095Estimate the annual revenue of one multiplex screen in a tier-1 Indian city.Equity researchCorporate finance
Try it first
Which input moves the answer most, and is hardest to guess?
Show the worked solution
Roughly Rs 4.4 crore a year, on the assumptions below. Five shows a day, 200 seats and 30% average occupancy give about 1.1 lakh admissions a year. At an average ticket of Rs 250 that is Rs 2.74 crore; food and beverage at Rs 130 a head adds Rs 1.42 crore; on-screen advertising adds perhaps Rs 0.2 crore. Every input is an assumption to state and then test.
What is the structure before any number?
Estimating what a hall earns is like estimating a restaurant: count the covers, then what each cover spends, then any income that does not depend on covers. Estimate each revenue stream separately: tickets and food both hang off admissions, while advertising depends on the screen, not the audience on the day. So the first job is admissions: shows a day times seats times occupancy times days.
Assume five shows a day on a 200-seat screen, open every day. Occupancy is the soft input: a weekend evening may be nearly full while a Tuesday matinee is mostly empty. Build it rather than guess it: if weekdays run at 20% and weekends at 55%, the weighted average is (5 x 20% + 2 x 55%) / 7, about 30%.
Stream Driver Assumption Rs crore a year Tickets admissions x average ticket 109,500 x Rs 250 2.74 Food and beverage admissions x spend per head 109,500 x Rs 130 1.42 Advertising per screen Rs 20 lakh 0.20 Total 4.36 Every price, occupancy and spend figure is an illustrative assumption, not an industry statistic. About 1.09 lakh admissions a year support Rs 2.74 crore of tickets and Rs 1.42 crore of food and beverage, with advertising a small extra, for about Rs 4.4 crore a year from one screen. How do you know the number is sensible?
Check it three ways. Per day: Rs 4.4 crore over 365 days is about Rs 1.19 lakh, which is 300 admissions spending about Rs 400 each in total, plausible for a screen with five shows. Per seat: about Rs 2.2 lakh a year. And the mix: food at about a third of revenue is the kind of share multiplex operators discuss, and it is high-margin money. The softest input is occupancy: every 10 points on it moves revenue by about Rs 1.4 crore, because it drives tickets and food together.
Say what revenue is not. Gross ticket revenue includes entertainment taxes in some form, and a large share of net ticket income goes to the film's distributor. Confirm current tax rates and typical revenue-sharing terms before using the figure for anything beyond a size estimate. Food, by contrast, the operator keeps in full, which is why its share matters to profit far more than its share of revenue suggests.
Where candidates lose it
The common error is assuming full houses: 5 shows x 200 seats x 365 days at Rs 250 is over Rs 9 crore from tickets alone, more than three times the ticket estimate. Average occupancy across every show, including weekday mornings, is far below a packed Friday night.
The second loss is stopping at tickets. Food and beverage is roughly a third of revenue on these assumptions and a larger share of profit. An interviewer asking about a multiplex wants to hear that you know the business is partly a restaurant with a screen attached.
What the interviewer asks next
- How would a premium recliner screen with 60 seats compare, and why?
- What share of this revenue would you expect the operator to keep after paying the distributor and taxes, and what would you check?
- A new release fills the screen to 70% for two weeks. How much does that add to the year?
