Investment Banking puzzles, solved step by step

Puzzles: 100
Traced to a firm: 36
Topics: 12
Hard: 29

Showing 1–10 of 19 · filtered from 100Clear filters

002A 10 x 10 x 10 cube is built from small unit cubes and the outside surface is painted green. How many small cubes have green paint on them, and how many have none?Mental maths and countingCoreTD SecuritiesNew York · 2024
Try it first
Quick instinct: how many small cubes are never painted?
Show the worked solution
488 small cubes are painted and 512 are not. The unpainted ones form a hidden core with one layer peeled off every side, so the core is 8 x 8 x 8, which is 512. The whole cube is 1,000, so 1,000 minus 512 leaves 488 with at least one painted face.
Why count the cubes you cannot see?
Picture a mango with its skin peeled. Measuring the skin piece by piece is fiddly; measuring the fruit left inside and subtracting from the whole is easy. The unpainted cubes form one clean block, so counting them and subtracting is faster and harder to get wrong than adding up the painted surface. Peeling one layer from both sides of each dimension takes 10 down to 8.
Each face of the big cube shows 8 corner cubes with three painted faces, 96 edge cubes with two and 384 face-centre cubes with one. They add to 488 painted cubes, and the 8 x 8 x 8 core of 512 cubes is never painted.
How do you check 488 the other way?
Count the surface directly, taking care not to double count. There are 8 corners, 12 edges each carrying 8 cubes once the corners are removed, and 6 faces each carrying an 8 x 8 centre. That gives 8 plus 96 plus 384, which is 488. Two methods agreeing is exactly what the interviewer wants to hear.
The relationship
$\text{painted} = n^3 - (n-2)^3 = 1000 - 512 = 488$
n cubes along one edge, here 10
(n-2)^3 the hidden core after peeling one layer from each side
What it says in wordsThe painted cubes are everything minus the core you cannot see.
Where candidates lose it
The fast wrong answer is 600: six faces of 100. It counts every edge cube twice and every corner cube three times. Candidates who start from the surface usually end up correcting on the fly and lose the room.
Start from the inside. Say the core formula, give 512 and 488, then offer the corner, edge and face split as a check.
What the interviewer asks next
How many small cubes have exactly two painted faces?
What size cube has as many unpainted as painted small cubes, roughly?
Now paint only the top and bottom. How many cubes are painted?
Asked at TD Securities, Generalist, New York, 2024 (Wall Street Oasis): If I gave you a 10x10x10 cube and I painted the surface green, how many cubes are green?
006You have a 3-litre bottle, a 4-litre bottle and an unlimited tap, and no way of marking the bottles. How do you measure exactly 2 litres, and which whole-litre volumes can you make at all?Logic and brainteasersCoreNomuraNew York · 2026
Try it first
What is the fewest number of fills and pours that leaves exactly 2 litres in one bottle?
Show the worked solution
Fill the 3-litre bottle, pour it into the 4, fill the 3 again and pour until the 4 is full: 2 litres are left in the 3-litre bottle. That is four moves. Because 3 and 4 share no common factor, fills and pours can build every whole number of litres, so any total from 1 to 7 is possible across the two bottles.
What does each move actually measure?
Think of paying for something with only Rs 3 and Rs 4 coins. You can pay Rs 2 by handing over two Rs 3 coins and taking a Rs 4 coin back as change. The bottles work the same way. Every fill adds a full bottle and every pour into a full bottle sets one bottle's worth aside, so the volumes you can make are sums and differences of 3s and 4s. Two litres is 3 plus 3 minus 4: you draw two small bottles from the tap, the big bottle swallows 4 of those 6 litres, and 2 are left.
Filling the 3-litre bottle twice and pouring into the 4-litre bottle leaves 2 litres behind in four moves, and because 3 and 4 share no common factor, every total from 1 to 7 litres can be built from the two bottles.
Is there a second route, and which volumes are out of reach?
Start from the big bottle and it still works, only slower. Fill the 4, pour into the 3 to leave 1, empty the 3, move the 1 litre across, fill the 4 again and top up the 3, which takes 2 litres and leaves 2 in the big bottle. That is six moves, 4 plus 4 minus 3 minus 3. Saying both routes and choosing the shorter one shows the interviewer you searched the problem rather than remembered it. Write each state as a pair, small bottle first, so neither of you loses track.
For the second half of the question, use BezoutA result in number theory: whole-number combinations of two numbers produce exactly the multiples of their highest common factor, and nothing else.'s rule: two bottle sizes can measure exactly the multiples of their highest common factor. The highest common factor of 3 and 4 is 1, so every whole number of litres can be built, limited only by capacity: up to 4 in one bottle and 7 across both. Contrast a 4 and a 6: their common factor is 2, so 3 litres is impossible however long you pour.
The relationship
$2 = 2\times 3 - 1\times 4 \qquad \gcd(3,4) = 1$
2 x 3 two fills of the 3-litre bottle
1 x 4 one full 4-litre bottle set aside
gcd(3,4) the highest common factor of the two sizes, here 1
What it says in wordsAny volume that is a whole-number mix of 3s and 4s can be poured, and because 3 and 4 share no factor, that covers every whole number.
Where candidates lose it
Candidates start pouring at random and narrate a dozen moves, losing track of which bottle holds what. The interviewer cannot follow it and neither can they. Write the state as a pair, small bottle first, and say each pair out loud.
The second loss is the second half of the question. Showing you can make 2 litres is not the same as saying which volumes are possible. Give the rule, that 3 and 4 share no common factor so every total from 1 to 7 works, and one pair of sizes where it fails.
What the interviewer asks next
With a 4-litre and a 6-litre bottle, can you measure 3 litres?
What is the fewest number of moves to leave exactly 1 litre in a bottle?
With a 5-litre and a 3-litre bottle, how do you measure 4 litres?
Asked at Nomura, Equity Capital Markets, New York, 2026 (Wall Street Oasis): How much water can you fill using 1 3liter and 1 4liter bottle using each other?
007A five-year bond pays an 8% annual coupon, and similar bonds now yield 10%. Roughly what is it worth per Rs 100 of face value, and why is it below par?Rates, risk and optionsCoreJ.P. Morgancloumbus · 2026
Try it first
Before you calculate: roughly where does the bond trade?
Show the worked solution
About Rs 92.4 per Rs 100 of face value. Discount the five Rs 8 coupons and the Rs 100 repayment at 10%: the coupons are worth Rs 30.33 today and the repayment Rs 62.09. It sits below par because it pays Rs 2 a year less than a new bond, and a buyer wants those five years of shortfall, worth Rs 7.58 today, taken off the price.
How do you price it from first principles?
Imagine you let a flat on a five-year lease at Rs 8,000 a month, and every similar flat now fetches Rs 10,000. Someone buying your lease will pay less for it, by roughly the rent you miss over the remaining term. A bond is the same lease on money. A bond's price is every future payment discounted at the yield the market now demands, so when that yield rises above the coupon, the price has to fall below par. At 10%, each Rs 8 coupon and the final Rs 100 are worth less today the further away they sit.
The four Rs 8 coupons are worth between Rs 7.27 and Rs 5.46 today and the final Rs 108 is worth Rs 67.06, so the bond is worth Rs 92.42, exactly Rs 2 a year of shortfall times the annuity factor of 3.79 below par.
The relationship
$P = \sum_{t=1}^{5} \frac{8}{1.10^t} + \frac{100}{1.10^5} = 30.33 + 62.09 = 92.42$
8 the annual coupon per Rs 100 of face value
1.10^t the growth factor at the 10% market yield for t years
100 the face value repaid at the end of year 5
What it says in wordsThe price is today's value of every coupon plus today's value of the final repayment, all at the yield the market now demands.
Is there a shortcut that skips most of the discounting?
Yes, and it is the one to use out loud. Price equals par minus the yearly coupon shortfall times the annuity factor: 100 minus 2 x 3.79 is 92.42. The annuity factorThe present value of Rs 1 a year for a set number of years. At 10% for five years it is about 3.79. is the only number that needs any work, and at 10% for five years it is close to 3.8. The same rule runs the other way: a bond paying above the market yield trades above par by the extra coupon times the annuity factor.
Two limits are worth one sentence each. The yield must come from bonds of the same maturity and credit quality, which is what similar bonds means; in today's market you would read it off comparable issues. Real bonds also pay coupons twice a year in many markets and trade with accrued interest, which shifts the answer by small amounts. For an interview answer, annual discounting is the expected level.
Where candidates lose it
The common slip is to discount at the coupon rate. That always returns exactly Rs 100 and misses the point of the question: the coupon sets the cash, the market yield sets the discounting.
The other loss is a quick guess of Rs 98 because the coupon is 2 points short. That counts one year of shortfall instead of five, and ignores discounting. Name the five years of missing Rs 2 and the annuity factor, and Rs 92.4 follows.
What the interviewer asks next
If yields fell to 6%, roughly what would the bond be worth?
Which moves more for a one point rise in yield: this bond or a 20-year bond with the same coupon?
With yields held at 10%, what happens to the price as the bond approaches maturity?
Asked at J.P. Morgan, Generalist, cloumbus, 2026 (Wall Street Oasis): How would you price a bond in today's market

008How many taxis are operating in Hong Kong's Central district at a busy weekday lunchtime?Estimation and market sizingCoreHSBCCentral · 2026

Try it first

What should your first sentence be, before any number?

Show the worked solution

Roughly 2,000 to 2,500 taxis, inside a defensible range of about 1,000 to 4,000. Assume 300,000 people in Central at lunch, 2% of them taking a taxi trip that touches the district in the peak hour, and each trip spending 15 minutes inside it: 1,500 cabs occupied at any moment. Add half as many again cruising or queuing empty and you reach about 2,250.

Why count trips and minutes rather than cabs?

Picture a busy restaurant. If 60 diners arrive an hour and each stays half an hour, about 30 seats are taken at any moment, whatever is on the menu. That rule, known as Little's lawThe number of items in a system on average equals the rate they arrive multiplied by how long each one stays., turns a flow into a count. The taxis in Central at one moment equal the trips touching Central per hour multiplied by the hours each trip spends there, plus the cabs that are empty. You cannot see cabs from an interview room, but you can reason about people and journeys.

Three hundred thousand people at lunch, 2% taking a taxi trip in the hour and 15 minutes per trip inside the district give 1,500 occupied cabs; adding empty cabs gives about 2,250, inside a range of 1,050 to 4,200.

Where do the numbers come from, and which one moves the answer most?

Every number is an assumption you state, not a fact you recall. Central is a dense office district, so assume 250,000 office workers plus 50,000 visitors and shoppers at lunch. Most walk or take the train; assume 2% take a taxi trip that starts or ends in Central in the busiest hour, which is 6,000 trips. A cab picking up, crawling through lunchtime traffic and dropping off spends perhaps 15 minutes in the district per trip. The minutes-per-trip assumption moves the answer as much as the head count does, so say it slowly and invite challenge on it. Empty cabs cruising or waiting at ranks add about half again.

Assumption	Low	Base	High
People in Central at lunch	250,000	300,000	350,000
Share taking a taxi trip that hour	1.5%	2%	2.5%
Minutes inside Central per trip	12	15	18
Empty cab uplift	x 1.4	x 1.5	x 1.6
Taxis in Central	1,050	2,250	4,200

Every input is an illustrative assumption; moving all four together gives the range.

How do you sanity-check it from the supply side?

Come at it from the fleet. Suppose the city has about 18,000 licensed taxis, a number you would state as an assumption and check against the current licence count, and the busiest business district holds 10% to 15% of them at peak. That gives 1,800 to 2,700. Two methods landing in the same range is worth more than either number on its own. If they had disagreed by a factor of three, you would say which assumption you trust less and why.

Where candidates lose it

Candidates jump straight to a number, or try to recall the city's taxi count and multiply by a share they cannot defend. The interviewer is scoring the structure, so a remembered figure with no logic behind it earns very little.

The second loss is false precision. Saying 2,250 as if it were measured sounds naive; give the central figure, the range, and the one assumption that would move it most.

What the interviewer asks next

How would your answer change at 3 am?
How many taxi trips start in Central across a whole weekday?
Which single assumption would you research first, and how would you check it?

Asked at HSBC, Sales and Trading, Central, 2026 (Wall Street Oasis): How many taxis are in HK central How many beds in the nyc hotel

009A company has Rs 100 of interest expense: Rs 50 paid in cash and Rs 50 paid in kind. The tax rate is 40%. Walk the effect through the three statements.Accounting riddlesCoreMizuhoNew York · 2026
Try it first
What happens to the company's cash?
Show the worked solution
Net income falls Rs 60, cash falls Rs 10, debt rises Rs 50 and retained earnings fall Rs 60. The full Rs 100 is expensed, so pre-tax income drops 100 and, after 40% tax, net income drops 60. The cash flow statement adds back the Rs 50 of PIK as a non-cash expense. On the balance sheet the PIK accrues to the debt, and assets of minus 10 equal liabilities and equity of plus 50 minus 60.
What does paid in kind mean in plain terms?
Suppose you owe a friend Rs 100 of interest, pay Rs 50 in cash and write an IOU for the other Rs 50. Your wallet is Rs 50 lighter, and you now owe Rs 50 more than before. Paid in kindInterest settled by adding it to the loan principal instead of paying cash. Often shortened to PIK. interest works exactly like that IOU. PIK interest is a real expense paid with more debt instead of cash, so it reduces profit while adding to the loan. That one sentence tells you where every number in the walk will land.
Net income falls Rs 60 after the Rs 40 tax saving, the Rs 50 of PIK is added back so cash falls only Rs 10, and on the balance sheet debt rises Rs 50 while retained earnings fall Rs 60, which balances the Rs 10 drop in cash.
Why does cash fall by only Rs 10?
Because tax is worked out on the whole expense, not just the cash part. Assume both halves of the interest are tax deductible, which is the usual set-up for this question; real deductibility rules vary by country and are often capped, so say the assumption. The Rs 100 expense saves Rs 40 of tax, and the only cash going out is the Rs 50 of cash interest, so cash falls Rs 50 minus Rs 40, which is Rs 10. On the cash flow statement the same Rs 10 appears as net income of minus 60 plus the Rs 50 PIK add-back.
The relationship
$\Delta \text{Cash} = \underbrace{-100\times(1-0.40)}_{\text{net income}} + \underbrace{50}_{\text{PIK add-back}} = -60 + 50 = -10$
-100 x (1 - 0.40) net income after the full expense and the 40% tax saving
50 the PIK interest, expensed but not paid in cash
What it says in wordsCash moves by net income plus any expense that was not paid in cash, which here is the PIK half.
How do you prove the balance sheet balances?
Say it in one breath. Assets fall 10 through cash. Liabilities rise 50 because the PIK interest is added to the principal of the debt. Equity falls 60 through retained earnings. Minus 10 on the asset side equals plus 50 minus 60 on the other side, so the balance sheet balances. Saying the check out loud is what turns a recited answer into a reasoned one, and it catches the slip of forgetting where the PIK went.
Where candidates lose it
The usual slip is to treat PIK as if it never touched the income statement, so net income falls only 30 and the balance sheet refuses to balance. PIK is a full expense; it simply is not paid in cash.
The second slip is losing the PIK after the add-back. It does not vanish: it accrues to the principal of the debt, and that Rs 50 increase is what makes the balance sheet tie.
What the interviewer asks next
What changes if the PIK interest is not tax deductible?
Next year interest is charged on the larger principal. What happens to the three statements?
Why would a borrower accept a PIK note at a higher rate than cash-pay debt?
Asked at Mizuho, Generalist, New York, 2026 (Wall Street Oasis): walk through 100 interest expense, 50 cash interest, 50 pik interest, 40 tax rate
010A company trades at 10x EV/EBITDA with a 20% EBITDA margin. What is its EV/Revenue multiple, and if net debt equals one year of EBITDA, what is its price-to-sales ratio?Valuation riddlesCoreHoulihan LokeyChicago · 2026
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What is the EV/Revenue multiple?
Show the worked solution
EV/Revenue is 2.0x and price to sales is 1.8x. Take Rs 100 of revenue. A 20% margin gives EBITDA of Rs 20, and at 10x the enterprise value is Rs 200, two times revenue. Net debt equals one year of EBITDA, Rs 20, so equity value is Rs 200 minus Rs 20, which is Rs 180, or 1.8 times revenue.
How do multiples convert into one another?
Think of a corner shop priced at 10 years of profit, where profit is a fifth of takings. Priced against takings, it costs two years' worth: 10 times a fifth. An enterprise value multiple converts into another by the ratio of their denominators, so EV/Revenue equals EV/EBITDA times the EBITDA margin. Working per Rs 100 of revenue keeps every step visible: EBITDA Rs 20, enterprise value Rs 200.
Per Rs 100 of revenue, a 20% margin gives EBITDA of Rs 20 and a 10x multiple gives enterprise value of Rs 200, so EV/Revenue is 2.0x; taking off net debt of Rs 20 leaves equity of Rs 180 and price to sales of 1.8x.
The relationship
$\frac{EV}{Rev} = \frac{EV}{EBITDA}\times\frac{EBITDA}{Rev} = 10\times 0.20 = 2.0 \qquad \frac{P}{S} = \left(10 - 1\right)\times 0.20 = 1.8$
EV/EBITDA the enterprise multiple given, 10x
EBITDA/Rev the margin, 20%
10 - 1 the multiple less net debt measured in years of EBITDA
What it says in wordsMultiply by the margin to move from EBITDA to revenue, and subtract net debt in years of EBITDA to move from enterprise value to equity.
Why is price to sales lower than EV to revenue here?
Price to sales is an equity multiple: the market value of the shares over revenue. To reach it from enterprise value you cross the equity bridgeThe steps from enterprise value to equity value: subtract debt and similar claims, add cash.. Equity value is enterprise value less net debt, so an equity multiple sits below the enterprise multiple when a company has net debt, and above it when it holds net cash. Net debt of one year's EBITDA is Rs 20 per Rs 100 of revenue, which takes Rs 200 down to Rs 180, or 1.8x.
The limitation to state is why bankers prefer one family over the other. Revenue belongs to every funder of the business, so comparing it with enterprise value is consistent; comparing it with equity value alone mixes a whole-business line with one funder's slice. Two companies with identical operations but different debt will show the same EV/Revenue and different price to sales ratios.
Where candidates lose it
The classic slip is dividing by the margin instead of multiplying, which gives 50x. It should fail the smell test at once: fifty times revenue at a 20% margin is 250 times EBITDA. Check direction by asking whether the new multiple should be bigger or smaller than the old one.
The second slip is forgetting the bridge and answering 2.0x for price to sales too. Enterprise and equity multiples have different numerators, and net debt is what separates them.
What the interviewer asks next
If the company held net cash of one year's EBITDA instead, what would price to sales be?
If D&A is 5% of revenue, what is EV/EBIT?
Why do bankers rarely lean on price to sales for companies carrying heavy debt?
Asked at Houlihan Lokey, Private Funds Advisory, Chicago, 2026 (Wall Street Oasis): Valuation ratio questions like if EV/EBITDA is 10x, what is
015Without a calculator, what is 9 to the power of 6?Mental maths and countingCoreNomuraTokyo · 2025
Try it first
Before computing anything, which size is right?
Show the worked solution
531,441. Rewrite 9 to the 6th as the square of 9 cubed. 9 cubed is 729. Then square 729 by splitting it into 700 plus 29: 700 squared is 490,000, twice 700 times 29 is 40,600, and 29 squared is 841. They add to 531,441. As a check, it should be a little over half a million, because 0.9 to the 6th is about 0.53.
How do you keep every step in your head?
Think of carrying a heavy box up six floors: you take it in two flights of three with a rest between, not six lifts in a row. Rewriting a power as the square of a smaller power cuts the work to one easy cube and one square you can split. 9 squared is 81, and 81 times 9 is 729, so 9 cubed is 729. Then 9 to the 6th is 729 squared, and squaring a number near a round one is the most practised move in mental maths.
Nine cubed is 729, and squaring 729 as 700 plus 29 gives a 490,000 block, two strips of 20,300 and an 841 corner, which add to 531,441.
The relationship
$9^6 = (9^3)^2 = 729^2 = (700+29)^2 = 490{,}000 + 2(700)(29) + 29^2 = 531{,}441$
9^3 729, nine cubed
(700 + 29)^2 the square split into a round part and a remainder
2(700)(29) the two strips, 20,300 each and 40,600 together
What it says in wordsSquare a number by splitting it into a round part and a remainder; the cross term counts twice.
How do you check it before saying it?
Three quick checks. An even power of 9 ends in 1, because 81 does, and 531,441 ends in 1. Any power of 9 is divisible by 9, so its digits must sum to a multiple of 9: 5 + 3 + 1 + 4 + 4 + 1 is 18. And the size is right: 9 is 10% below 10, and six 10% trims leave about 53% of a million. A digit check and a size check together catch nearly every slip in the cross term, which is where most mental errors happen.
A second route, if you prefer it: 9 to the 6th is also 81 cubed. 81 times 81 is 6,561, and 6,561 times 81 is 6,561 times 80 plus 6,561, which is 524,880 plus 6,561, giving 531,441 again. Saying one route and confirming with the other is worth more than speed.
Where candidates lose it
The usual loss is multiplying 9 by itself six times in a row and dropping a digit somewhere in the five-digit middle steps. By the time you reach 59,049 times 9, the interviewer has watched you struggle for a minute.
The other loss is saying the number without a check. Give the answer, then the two-second test: it ends in 1 and its digits sum to 18.
What the interviewer asks next
What is 11 to the power of 4?
What are 99 squared and 999 squared?
Is 2 to the power of 20 bigger or smaller than a million, and by how much?
Asked at Nomura, Generalist, Tokyo, 2025 (Wall Street Oasis): I think one of the math questions was 9 to the power of 6
017Free cash flow of Rs 100 crore arrives every year for five years and the discount rate is 10%. How much does the mid-year convention add to the value, and why?DCF and cost of capitalCoreLazardNew York · 2026
Try it first
How much does the mid-year convention add?
Show the worked solution
It adds about Rs 18.5 crore, or 4.9%, taking the value from Rs 379.1 crore to Rs 397.6 crore. The mid-year convention assumes each year's cash arrives evenly through the year, so on average halfway through rather than at the end. Every cash flow is then discounted for half a year less, which multiplies each present value by 1.10 to the power of one half, 1.0488.
Why would cash arrive in the middle of the year?
A shop does not collect its year's takings in one lump on the last day of March; money comes in every day. A DCF that discounts each year's cash flow as if it all arrived on the final day is too harsh. The mid-year convention treats each year's cash flow as arriving, on average, halfway through the year, so it is discounted for t minus one half years instead of t. For a business with steady receipts that is the more accurate assumption, and it is the default in many banks' models.
Moving each Rs 100 crore cash flow from the end of its year to the middle lifts its discount factor by the same ratio, so the five-year value rises from Rs 379.08 crore to Rs 397.58 crore, an uplift of 4.88%.
The relationship
$\sum_{t=1}^{5} \frac{100}{1.10^{\,t-0.5}} = 1.10^{0.5} \times \sum_{t=1}^{5} \frac{100}{1.10^{\,t}} = 1.0488 \times 379.08 = 397.58$
t - 0.5 each year's cash treated as arriving at the middle of the year
1.10^0.5 the gain from discounting every cash flow for half a year less
What it says in wordsShifting every cash flow six months earlier multiplies the whole value by the square root of one plus the discount rate.
Why is the uplift exactly the square root of 1.10 minus one?
Because the shift is the same for every cash flow. Moving a payment six months earlier multiplies its present value by 1.10 to the power of one half, whatever year it sits in. Since every cash flow gets the same uplift, the whole value rises by the same 4.88%, and neither the size nor the pattern of the cash flows changes that. Half the discount rate, 5%, is a fair first approximation to say out loud; at a 20% rate the exact uplift is 9.5%, against the 10% the approximation would give, so the shortcut weakens as rates rise.
Where should you not apply it?
Two cautions. A terminal valueThe value of all cash flows beyond the forecast years, usually from a growing perpetuity or an exit multiple. built on a perpetuity of flows is usually discounted on the same mid-year basis, but one built on an exit multiple is not, because a sale happens at a point in time, the end of the final year. Shifting an exit-multiple terminal value half a year earlier overstates the answer, and an interviewer who asks about the convention is often fishing for exactly that. For seasonal businesses that collect most cash late in the year, the convention itself flatters the value.
Where candidates lose it
The usual slip is to say the convention changes the cash flows, or that it only affects the first year. It changes timing only, and it moves every cash flow by the same six months, so the uplift applies to all of them.
The second slip is applying it to a terminal value built on an exit multiple. A sale happens at a moment, so that value stays discounted for the full five years; candidates who shift it too overstate the value and get caught on the follow-up.
What the interviewer asks next
If the discount rate were 20%, what would the convention add?
Should the mid-year convention apply to a terminal value built on an exit multiple?
For a business that bills most customers in its final quarter, is the convention still appropriate?
Asked at Lazard, Investment Banking, New York, 2026 (Wall Street Oasis): Asked about SBC, LBOs, Advanced accounting questions and mid-year conventions
024Size the annual market for wedding catering in India, in Rs crore.Estimation and market sizingCoreRothschild & CoNew York · 2026
Try it first
Which structure gives the most defensible answer?
Show the worked solution
Roughly Rs 2.3 lakh crore a year, on stated assumptions. Assume about 90 lakh weddings a year, from a population of about 140 crore. Split them into budget, mid-range and premium tiers, each with its own plate count and cost per plate. Budget weddings contribute about Rs 47,000 crore, mid-range Rs 81,000 crore and premium about Rs 1 lakh crore: 5% of weddings, 44% of the spend.
How many weddings happen a year?
Start from people, not from a remembered statistic. Assume a population of about 140 crore, a figure to confirm, and an average lifespan near 70 years, so roughly one seventieth of people, 2 crore, reach marrying age each year. Assume 90% marry: 1.8 crore people, or 90 lakh weddings. A count built from cohorts can be checked line by line, which is what makes it defensible in the room. One caveat is worth saying: a young population has larger cohorts than one seventieth, so this may undercount a little.
Why split by tier rather than use one average wedding?
Think of a school canteen and a five-star hotel both serving lunch. Averaging their prices and their customer counts separately, then multiplying, gives a number neither of them earns. Big weddings have both more guests and a higher cost per plate, so averaging guests and price separately understates the market. On the tiers below, the average-wedding shortcut, 435 plates at Rs 400, gives Rs 1.57 lakh crore, about 32% less than the tiered Rs 2.29 lakh crore. Plates here count every guest meal across all the functions of a wedding, and catering means food only, not venue or decoration.
About 90 lakh weddings a year, split into budget, mid-range and premium tiers with their own plate counts and prices, give about Rs 2,29,500 crore of catering, while one average wedding multiplied out gives only Rs 1,56,600 crore.
Tier Share of weddings Weddings Plates Rs per plate Rs crore
Budget 70% 63 lakh 300 250 47,250
Mid-range 25% 22.5 lakh 600 600 81,000
Premium 5% 4.5 lakh 1,500 1,500 1,01,250
Total 100% 90 lakh 2,29,500
Every input is an illustrative assumption stated for the estimate, not a measured figure.
Which assumption moves the answer most?
The premium tier. It is 5% of weddings and 44% of the value, so a change in its plate count or price moves the total more than any change in the budget tier. When one segment dominates the value, spend your sanity checks there: is 1,500 plates across several functions at Rs 1,500 a plate plausible for the top twentieth of weddings? Halve the premium tier's value and the total falls to about Rs 1.8 lakh crore, which is the honest low end of the range to quote.
Where candidates lose it
The common loss is one average wedding: a few hundred guests at a few hundred rupees a plate, times the number of weddings. It sounds reasonable and quietly drops about a third of the market, because the weddings with the most guests also pay the most per plate.
The second loss is reciting a wedding-industry figure from an article. The interviewer wants a structure built from people, tiers and plates, with every number said as an assumption.
What the interviewer asks next
How would you size the decoration market for the same weddings?
How does the wedding season affect the capacity a caterer needs?
How would you check the premium tier's assumptions with a few phone calls?
Asked at Rothschild & Co, Generalist, New York, 2026 (Wall Street Oasis): 1st round all technical focused mainly on DCF and Eq Val and Enterprise Value questions, mental math, and some market sizing

Tier	Share of weddings	Weddings	Plates	Rs per plate	Rs crore
Budget	70%	63 lakh	300	250	47,250
Mid-range	25%	22.5 lakh	600	600	81,000
Premium	5%	4.5 lakh	1,500	1,500	1,01,250
Total	100%	90 lakh			2,29,500

027Equity value is Rs 1,000 crore. The company has Rs 400 crore of debt, Rs 150 crore of cash, Rs 100 crore of preference shares, Rs 50 crore of minority interest and a stake in an associate worth Rs 80 crore. What is enterprise value?Enterprise value and dilutionCoreBarclaysLondon · 2026