Financial Analysis puzzles, solved step by step

Its beta is zero, yet its expected return is minus 8%. Beta measures movement with the market, and a slot machine's payouts are random and unrelated to the market. CAPM would give a zero-beta asset the risk-free rate, say 7% a year, so the machine falls short by at least 15 points. There is no contradiction: CAPM prices assets bought as investments, and a slot machine is bought as entertainment.

How can something so risky have a beta of zero?

Think of an umbrella seller and an ice cream seller in the same town. Each has a volatile income, but whether it rains has nothing to do with the stock market. BetaHow much an asset tends to move when the market moves, measured as its covariance with the market divided by the variance of the market. measures how an asset moves with the market, not how much it moves, so a gamble driven by a random number generator has a beta of zero. The slot machine is about as volatile as anything in a town, but all of that risk is the kind a diversified owner can spread away, and in this case the casino does exactly that across thousands of players.

Why does CAPM not give it the risk-free rate?

CAPM says expected return equals the risk-free rate plus beta times the equity risk premium. With beta of zero that is just the risk-free rate, 7% a year in this example. The machine instead returns minus 8% on every stake, and a stake lasts seconds, so over a year of play the gap is far wider than the 15 points the two headline numbers suggest. In CAPM language that is a large negative alphaThe return an asset earns above or below what its beta implies under CAPM..

So is CAPM wrong?

No, it is answering a different question. CAPM describes the prices of assets that diversified investors hold to earn a return, where anyone could sell an overpriced asset short. Nobody plays a slot machine for return; players pay 8% of each stake for entertainment, the way a cinema ticket has a negative return. And you cannot short a single slot machine to collect the edge. The only way to take the other side is to own the casino, which needs licences, buildings and capital, and the casino's return on that capital is what an investor would compare with CAPM. Say that and the interviewer hears that you know where a model applies, not just its formula.

531,441. Split the power: 9 to the 6th is 9 cubed, squared, and 9 cubed is 729. Square 729 as (730 minus 1) squared: 730 squared is 532,900, less twice 730, which is 1,460, plus 1, gives 531,441. Check it: an even power of 9 ends in 1, the digits add to 18, and 0.9 to the 6th is about 0.53, so the size is right.

How do you break a big power into steps you can hold in your head?

Think of carrying a heavy suitcase up six floors: you rest on the landings. Split the exponent into pieces you know, 6 = 3 x 2, so 9 to the 6th is 9 cubed, squared. Most people know 9 squared is 81 and 9 cubed is 729. That turns the question into one square, 729 times 729, which is still awkward until you move it next to a round number.

Why square 730 instead of 729?

Because 730 squared is easy: 73 squared is 5,329, so 730 squared is 532,900. The identity (a minus 1) squared equals a squared minus 2a plus 1 lets you square any number just below a round one with two easy corrections. Twice 730 is 1,460. So 532,900 less 1,460 is 531,440, and adding 1 gives 531,441. Each step is small enough to say out loud while you do it.

How do you check it before you say it?

Three checks take seconds. The last digit of an even power of 9 is always 1, the digit sum of any power of 9 is divisible by 9, and 9 to the 6th is 0.9 to the 6th times a million. Here the digits 5, 3, 1, 4, 4, 1 add to 18, and 0.9 to the 6th is about 0.53, so the answer must be about 530 thousand. That last check catches the common slip of being off by a factor of ten. A second route also helps: 81 squared is 6,561, and 6,561 times 81 is 524,880 plus 6,561, again 531,441.

About 5,100 people, as a range of roughly 3,400 to 5,100. Take a floor plate of 25,000 square feet. After lifts, stairs and services about 80% is usable, 20,000 square feet. At 100 square feet a seat that is 200 seats, and at 85% occupancy about 170 people a floor. Thirty floors gives about 5,100. Roomier offices at 150 square feet a seat bring it down to about 3,400.

Why start from one floor?

Think of estimating the people in a cinema: you count the seats in one row, then the rows. A tower is the same: thirty copies of one floor, so estimate one floor carefully and multiply, because every assumption is easier to defend on a single floor you can picture. Define the answer too: people who work in the building, meaning assigned staff, not visitors and not the count present on any one day.

What goes into one floor?

Four assumptions, each said out loud. A floor plate of about 25,000 square feet, typical for a large commercial tower. About 20% of that is the coreThe central block of a floor holding lifts, stairs, toilets, shafts and service rooms, which cannot be used for desks., leaving 20,000 usable. At 100 square feet a seat, including aisles and meeting rooms, the floor holds 200 seats, and with 85% of seats assigned that is about 170 people. The rest are vacant desks, new hires not yet in, or space held for growth.

Which assumption would you flex, and how would you check it?

Seat density moves the answer most. A dense back office runs near 100 square feet a seat; a bank's front office with larger desks and more meeting rooms nearer 150. At 150 square feet a seat the tower holds about 3,400 people, so give the answer as about 3,400 to 5,100. Then trim for floors that hold no desks: if the lobby and a plant floor take two of the thirty, the dense case falls to about 4,760. A check from another side: assume a dozen lifts, each carrying about 15 people a trip on a round trip of about 3 minutes. That moves about 12 x 15 x 20, or 3,600 people an hour, which fits a building of a few thousand people arriving over a morning, not tens of thousands.

17 minutes. 1 and 2 cross (2 minutes) and 1 brings the torch back (1). Then 5 and 10 cross together (10), and 2 brings the torch back (2). Finally 1 and 2 cross again (2). The obvious plan, where the 1-minute person escorts everyone, takes 19 minutes because the two slowest walkers cost 15 minutes on separate trips but only 10 together.

Why does the obvious plan lose two minutes?

The escort plan sounds efficient: the fastest person walks each one across and runs back with the torch. It costs 2, 1, 5, 1 and 10, which is 19 minutes. The waste is that the 5 and the 10 cross on separate trips, so you pay both their times, 15 minutes, when one shared trip would cost only 10. Think of two slow friends who will hold up any group they walk with; the cheapest thing is to let them hold up the same group, once.

How do you make sure the torch is on the right side?

If 5 and 10 cross first, one of them has to bring the torch back, which costs at least 5 more minutes. So before the slow pair goes, a fast walker must already be waiting on the far side to carry the torch back. That is why 1 and 2 go first and 1 returns: it parks the 2 on the far side. After the slow pair crosses, the 2 brings the torch back, and the fast pair finishes together.

How do you show 17 cannot be beaten?

There must be three forward trips and two returns. The 10 must cross on some forward trip, costing 10. If the 5 crossed on a different forward trip, the forward trips alone would cost at least 10 + 5 + 2, which is 17, and the two returns add at least 2 more, so 5 and 10 must share a trip. The slow pair cannot go first, or one of them walks the torch back. So 1 and 2 go first, costing 2, and one of them returns. After the slow pair crosses, the only fast walker on the far side is whichever of 1 and 2 stayed, so the two returns cost 1 + 2 between them, and the last trip, 1 and 2, costs 2. That gives at least 10 + 2 + 2 + 1 + 2 = 17. A brute-force search over every schedule confirms 17.

Anywhere from about -0.75 to 0.95. Read each correlation as the cosine of an angle between two arrows. X is 78.5 degrees from Y, and Z is 60 degrees from Y. Z can swing to the same side as X, leaving them 18.5 degrees apart, or to the other side, 138.5 degrees apart. The cosines of those angles are 0.9485 and -0.7485.

Why can a correlation be drawn as an angle?

Think of three people walking away from the same lamp post. Knowing how far apart the first two point, and how far apart the second and third point, limits how far apart the first and third can point, but only loosely. If you standardise each variable, its correlation with another is the cosine of the angle between them, so correlations must behave like angles in space. A correlation of 0.2 is an angle of 78.5 degrees; 0.5 is 60 degrees.

Where does the formula come from, and when does it bite?

The three-by-three correlation matrix must not imply a negative variance for any mix of X, Y and Z, which means its determinant cannot go below zero. Solving that condition gives the formula above, the cosine rule for the difference and sum of two angles. The constraint is loose when the known correlations are weak and tight when they are strong. With 0.2 and 0.5, almost the whole scale stays open. With 0.9 and 0.9, X and Z must correlate at least 0.62: two things each closely tied to Y cannot drift far from each other. Say the practical use: a risk model that fills in missing correlations by hand can break this rule and produce a matrix that is not valid.

Equity falls from Rs 2,400 crore to Rs 800 crore, a 66.7% drop on a 20% fall in EV. Debt is 7 x 800 = Rs 5,600 crore. At 10x, EV is Rs 8,000 crore; at 8x it is Rs 6,400 crore. Debt keeps its claim, so the equity slice absorbs the whole Rs 1,600 crore. At 7x leverage, equity moves 3.3 times as fast as EV, and a 7x multiple wipes it out.

Why does equity fall so much further than the business?

Think of a flat bought for Rs 1 crore with a Rs 70 lakh home loan. If the flat's price drops 20% to Rs 80 lakh, the bank still wants its Rs 70 lakh, so the owner's stake falls from Rs 30 lakh to Rs 10 lakh, a two-thirds loss. Debt is a fixed claim in rupees, so any change in enterprise value lands entirely on the equity that sits on top. Here debt is 7 x 800 = Rs 5,600 crore. At 10x, EV is Rs 8,000 crore and equity is Rs 2,400 crore, only 30% of the value.

So what does 7x leverage tell you about sensitivity?

Leverage of 7x EBITDA means the debt alone is worth 7x EBITDA. Whenever the valuation multiple sits close to the leverage multiple, equity is a thin slice of the gap between them, and small changes in the multiple swing it hard. At 10x the gap is 3 turns; each turn of multiple is Rs 800 crore, a third of the equity. Software companies can carry this because their cash flows recur and their multiples are high, but the same 7x on a business valued at 8x leaves one turn of cushion. Say the limitation: the sum assumes debt is worth its face value, while in distress the debt itself would trade below par and soak up some of the loss.

About Rs 43. Each use ties up a Rs 10 note for a year, which at 10% costs you Rs 11 by year end, plus Rs 2 of electricity, and pays Rs 20. That is Rs 7 a year for ten years, and Rs 7 times the ten-year annuity factor of 6.1446 is Rs 43.01. If the electricity is paid at the start of each year the net is Rs 6.80 and the value Rs 41.78.

What is one use of the machine actually worth?

Think of lending a friend Rs 10 for a year and getting Rs 20 back. You doubled your note, but you also went a year without it, and that year had a price: whatever the money would have earned in the bank. The machine does not create Rs 10 a year; it creates Rs 20 at year end in exchange for Rs 10 today, and Rs 10 today is worth Rs 11 at year end at 10%. Take off Rs 2 of electricity and each use leaves Rs 7, received one year after you feed it the note.

Why does the timing of the electricity change the answer?

The question does not say when you pay for power. If you pay at the end of the year, the net is the Rs 7 above. If you pay at the start, alongside the note, the Rs 2 also costs you a year of interest, Rs 2.20 by year end, and the net drops to Rs 6.80, worth Rs 41.78. State the timing assumption out loud, because an interviewer who wrote this puzzle is listening for whether you notice that cash flows need a date. The other common answer, Rs 49.16, discounts Rs 8 a year and is wrong for a reason, not a rounding: it treats the Rs 10 note as free to borrow.

One check makes the answer believable. You could reproduce the machine with a bank loan: borrow Rs 10 at 10%, run the machine, repay Rs 11 and the Rs 2 of power, keep Rs 7. A buyer will pay up to the present value of that stream, and no more, because the bank can supply the money at 10% anyway.

Consolidated net income is Rs 250 crore, Rs 230 crore is attributable to the parent, and non-controlling interest on the balance sheet is Rs 120 crore. Control brings in all of the subsidiary's Rs 50 crore profit. The outside holders' 40%, Rs 20 crore, is shown as profit attributable to non-controlling interest. On the balance sheet, their 40% of Rs 300 crore of book equity sits as a separate line in equity.

Why take in all of a company you only partly own?

Think of a family that controls a shop it co-owns with a cousin. The family runs it, banks its takings and pays its bills, so to describe what the family controls you count the whole shop, then note that a share of the profit belongs to the cousin. Control, not ownership share, decides consolidation, so the parent adds 100% of the subsidiary's revenue, costs, assets and debt, then shows the minority's share of profit and equity on separate lines. That is why consolidated net income is 200 plus 50, Rs 250 crore, and not 200 plus 30.

Where does non-controlling interest show up on each statement?

On the income statement, net income of Rs 250 crore is split into Rs 230 crore for the parent's shareholders and Rs 20 crore for non-controlling interest. EPS uses the Rs 230 crore. On the balance sheet, non-controlling interest of Rs 120 crore sits inside total equity, next to the parent's own equity; if the subsidiary keeps its Rs 50 crore profit for the year, the line grows by Rs 20 crore. On the cash flow statement nothing is deducted, because the minority share of profit is not a cash payment; only dividends paid to the outside holders leave as cash, in financing. Non-controlling interest is a claim on the group by other shareholders, which is why an EV bridge adds it back alongside debt.

State your assumption: the minority is measured at its share of the subsidiary's book equity, with no fair-value uplift or goodwill allocated to it on acquisition. Under the full goodwill method the line would be larger. And note the boundary case: had the parent owned 40% without control, it would use the equity method, report the same Rs 230 crore of net income, but show none of the subsidiary's revenue or debt.

Market capitalisation is Rs 2,000 crore. With no other liabilities, assets equal debt plus equity. A D/E of 0.5 means debt is half of equity, so assets are 1.5 times equity and book equity is Rs 1,500 crore over 1.5, which is Rs 1,000 crore, with Rs 500 crore of debt. At 2.0x book, the market values that equity at Rs 2,000 crore.

How does a debt-to-equity ratio split the balance sheet?

Think of a Rs 15 lakh car bought with a loan that is half the size of your down payment. If the loan is half the down payment, the car cost one and a half down payments, so the down payment was Rs 10 lakh and the loan Rs 5 lakh. A D/E of 0.5 does not mean half the assets are debt; it means debt is half of equity, so assets are 1.5 times equity. Rs 1,500 crore over 1.5 gives book equity of Rs 1,000 crore and debt of Rs 500 crore.

What assumptions sit under the answer, and what could you add?

The question rules out other liabilities, such as payables and provisions, and that matters: a real balance sheet has plenty, and then assets are not just debt plus equity. Say the identity you are using, assets equal liabilities plus equity, before you lean on it. You can also go one step further than asked. With Rs 500 crore of debt and no cash given, enterprise value is about Rs 2,500 crore. And a P/B of 2.0 says the market thinks the assets earn more than their cost of capital; read it next to return on equity rather than on its own.

About 106 a year, on stated assumptions. Assume 15 crore domestic trips a year. A 180-seat jet, 85% full, flying 5 sectors a day for 350 days carries about 2.68 lakh passengers, so the fleet is about 560 jets. At 8% traffic growth it needs 1,209 in ten years, 65 more a year, plus about 41 retirements a year on a 20-year life.

How do you turn passengers into aircraft?

Think of a school deciding how many buses to buy. It counts the children who need a seat, divides by how many one bus can carry in a day, then adds buses for next year's bigger intake and for the old ones being scrapped. Aircraft demand is the same: fleet size is passenger trips divided by what one jet carries in a year, and new orders are fleet growth plus replacement. State each number as an assumption, because the interviewer cares about the structure first and the inputs second.

Start with traffic. Assume about 15 crore domestic passenger trips a year, and tell the interviewer you would check the current figure in the aviation regulator's monthly traffic data. A narrow-body has about 180 seats; assume 85% of them are filled, 5 sectors a day and 350 flying days. That is 267,750 passengers a jet a year, so today's fleet is about 560 jets.

Which assumption moves the answer most, and what did you leave out?

Growth carries more of the answer than replacement: at 8% a year the fleet more than doubles in ten years, adding 65 jets a year, while retirements on a 20-year life add 41. The number most worth defending is passengers per jet, because a sixth sector a day would cut the fleet by a sixth and every later number with it. Then name what you left out: international short-haul routes also fly narrow-bodies, airlines hold spare aircraft for maintenance, and engine problems can ground jets for months. Each pushes the true need above 106. Also say that orders and deliveries differ: airlines order years ahead, so order books can be far larger than a decade's need.