Investment Banking interview preparation

Questions

100

Traced to a firm

100

Firms

46

Updated

September 2026

Asked at

All firmsTSTruist Securities10Rothschild & Co8Centerview Partners7CSCredit Suisse7HWHarris Williams6Houlihan Lokey6Lazard6Mizuho6Barclays5Citi5Deutsche Bank5Evercore5Moelis & Company5MSMorgan Stanley5Piper Sandler5RCRBC Capital Markets5Goldman Sachs4Nomura4TD Securities4Bank of America3GSGuggenheim Securities3J.P. Morgan3Jefferies3Moody's3Perella Weinberg Partners3WPWarburg Pincus3WBWilliam Blair3HSBC2Lincoln International2Scotiabank2TPTPG2UBS2Wells Fargo Securities2Advent International1Apollo Global Management1Bain Capital1Balyasny Asset Management1BLBlackRock1BPBNP Paribas1General Atlantic1Invesco1Morningstar1PIMCO1STSociété Générale1SSState Street1WMWellington Management1

Topic

All topicsAccounting14Valuation21M&A10Markets and deals10Capital markets3LBO8Leveraged finance3Restructuring2Credit3Debt capital markets2Capital structure2Case and estimation11Brainteasers6Fit5

Level

AnyCoreIntermediateHard

Type

AnyTechnicalCaseBrainteaserFitMarket view

1. 091What angle is formed by the clock hands at 3:15?BrainteasersCoretechnicalCenterview PartnersInvestment Banking · Menlo Park · 2025

   Say this

   7.5 degrees. The minute hand is exactly on the 3, but the hour hand has moved a quarter of the way from 3 to 4. Each hour is 30 degrees, so a quarter of that is 7.5.

   Then walk it

   1. The clock face is 360 degrees over 12 hours, so each hour mark is 30 degrees apart.
   2. At 3:15 the minute hand sits exactly at the 3, which is 90 degrees from twelve.
   3. The hour hand does not stay on the 3. In 15 minutes it travels a quarter of the way to the 4, which is a quarter of 30 degrees, so 7.5 degrees past the 3.
   4. The gap between them is therefore 7.5 degrees.
   5. The general formula worth having: the angle equals the absolute value of 30 times the hour minus 5.5 times the minutes. Here that is 90 minus 82.5, which is 7.5.

   Where candidates lose it

   Answering zero, because you assumed both hands are on the 3. The hour hand moves continuously, and that is the entire point of the question. Say the formula afterwards to show it was not luck.

   Expect next

   • When is the next time the hands overlap exactly?
   • How many times a day do the hands overlap?
   • How many 0s are in 1000 factorial?

   Reported by candidates at Centerview Partners (Investment Banking, Menlo Park, 2025). Source: Wall Street Oasis.

2. 092I paint the surface of a 10x10x10 cube green. How many of the small cubes have green on them, and how many do not?BrainteasersIntermediatetechnicalTD SecuritiesGeneralist · New York · 2024

   Say this

   488 have green on them and 512 do not. Solve the easy half first: the unpainted cubes form an inner 8x8x8 block, which is 512. Subtract that from 1,000 to get 488 painted.

   Then walk it

   1. Total small cubes: 10 cubed is 1,000.
   2. Any cube not touching the surface is one layer in from every face. That leaves an 8 by 8 by 8 core, because you remove one layer from each of the two opposite sides in all three dimensions.
   3. 8 cubed is 512 unpainted.
   4. So painted is 1,000 minus 512, which is 488. Computing the painted faces directly is possible but far more error-prone.
   5. If they push further: 8 corner cubes have three painted faces, 96 edge cubes have two, and 384 face cubes have one. That sums to 488, which confirms the answer.

   Where candidates lose it

   Trying to count the painted cubes face by face and double-counting the edges and corners. Always solve for the interior and subtract. Saying 'I will do the easy side first' out loud is itself the signal they want.

   Expect next

   • How many have exactly two painted faces?
   • Generalise it for an n-cube.
   • Now do it for a 10x10x10 where I only paint the top and bottom.

   Reported by candidates at TD Securities (Generalist, New York, 2024). Source: Wall Street Oasis.

3. 093Lilypads double every day and cover the pond on day 30. On what day was the pond half covered?BrainteasersCoretechnicalHWHarris WilliamsGeneralist · Richmond · 2025

   Say this

   Day 29. If the area doubles every day, then the day before it was full it must have been exactly half. Work backwards, not forwards.

   Then walk it

   1. Doubling means the step from half to full takes exactly one day.
   2. Full on day 30 therefore means half on day 29.
   3. The instinct to halve the number of days and say 15 is the trap. On day 15 the pond is about one thirty-two-thousandth covered, since it doubles fifteen more times.
   4. The general principle: in exponential growth, almost all of the accumulation happens at the very end. That is why the answer feels wrong.
   5. It is worth naming the finance version, because that is why the question gets asked: compounding, and the danger of extrapolating an exponential trend from a small base.

   Where candidates lose it

   Saying day 15. It is the reflex answer and it is wrong by a factor of thirty thousand. Answer in one second, then add the exponential-growth observation so it reads as understanding rather than recall.

   Expect next

   • What does that tell you about compounding?
   • If I make 8 times my money in 6 years, what is my IRR?
   • How would you spot a business at the steep part of that curve?

   Reported by candidates at Harris Williams (Generalist, Richmond, 2025). Source: Wall Street Oasis.

4. 094How many aeroplanes are in the air at once?BrainteasersIntermediatetechnicalSTSociété GénéraleMergers and Acquisitions · New York · 2025HSBCSales and Trading · Hong Kong · 2026

   Say this

   Around ten to fifteen thousand. Build it from the fleet: roughly 25,000 commercial aircraft worldwide, each flying maybe 10 hours a day, so about 40 percent are airborne at any moment, which gives 10,000.

   Then walk it

   1. Start from a number you can defend: the global commercial fleet is on the order of 25,000 aircraft. If you do not know it, build it from airlines: a few hundred carriers averaging perhaps 80 aircraft.
   2. Utilisation: a commercial jet flies roughly 8 to 12 hours a day. Call it 10, which is about 40 percent of a 24-hour day.
   3. 25,000 times 0.4 gives 10,000 airborne on average.
   4. Then adjust for the peak-trough pattern. Air traffic is concentrated in daylight hours across the Northern Hemisphere, so the daytime peak might be 50 percent above average and the small hours well below. Peak perhaps 15,000.
   5. Then say what you excluded and why: private aviation, cargo and military would add to it, probably a few thousand more, and I have not counted them.
   6. Close with the sanity check: published flight-tracking figures sit in the same range, low to mid five figures, so the estimate holds.

   Where candidates lose it

   Guessing a number with no derivation, or getting lost in decimals. Market sizing is judged entirely on structure. State each assumption, keep the arithmetic round, and say which populations you left out.

   Expect next

   • How many taxis are in Hong Kong Central?
   • How many hotel beds are there in New York City?
   • How many books were sold in the US last year?

   Reported by candidates at Société Générale (Mergers and Acquisitions, New York, 2025); HSBC (Sales and Trading, Hong Kong, 2026). Source: Wall Street Oasis.

5. 095What is 301 times 447?BrainteasersIntermediatetechnicalGeneral AtlanticGeneralist · New York · 2026

   Say this

   134,547. Break 301 into 300 plus 1. Three hundred times 447 is 134,100, plus one more 447 gives 134,547.

   Then walk it

   1. Decompose to the nearest round number. 301 is 300 plus 1, and 300 is easy because it is 3 times 100.
   2. 447 times 3 is 1,341. Times 100 is 134,100.
   3. Add the remaining 447: 134,547.
   4. Announce the decomposition before you compute, so the interviewer can follow and so a slip in arithmetic does not look like a failure of method.
   5. The same trick handles most of these: round one number, multiply, then correct. For 19 times 63, do 20 times 63 minus 63.

   Where candidates lose it

   Attempting long multiplication in your head and losing a digit. These are speed-and-method tests. Decompose out loud, keep one running total, and offer the sanity check that the answer should be a bit over 134,000.

   Expect next

   • What is 19 times 63?
   • What is 1/7 as a decimal?
   • What is the square root of 6,241?

   Reported by candidates at General Atlantic (Generalist, New York, 2026). Source: Wall Street Oasis.

6. 096Why investment banking, and why this firm?FitCorephone / HireVueGoldman SachsInvestment Banking · New York · 2026CitiInvestment Banking · San Francisco · 2025TSTruist SecuritiesInvestment Banking · Charlotte · 2026Deutsche BankInvestment Banking · London · 2022Rothschild & CoInvestment Banking · London · 2025

   Say this

   Three beats: a specific moment that got you interested, what you did to test that interest, and one concrete reason for this firm that could not be copy-pasted to a competitor.

   Then walk it

   1. The origin has to be specific and true. A deal you followed, a project where you built a model, a company in your family, a case competition. Not 'I have always been passionate about finance'.
   2. Then the evidence that you tested it, because interest is cheap and action is not. A society, a self-taught model, an internship, a stock you have tracked for two years.
   3. Then why banking rather than the adjacent options, and be honest about the trade you are making. Something like: I want the transaction seat rather than the research seat because I want to be inside the execution, and I know what the hours cost.
   4. Then why this firm, with one fact that is true only of them: a specific deal, a sector franchise, the size of the analyst class, the staffing model. One real fact beats three generic compliments.
   5. Keep it to about ninety seconds and finish cleanly instead of trailing off. Then stop talking.

   Where candidates lose it

   A 'why this firm' answer that would work for any of their competitors. Interviewers hear forty versions a day and the generic ones blur. Name one thing only they do, and if you have spoken to someone there, say who and what they told you.

   Expect next

   • Why you over the other candidates from your university with the same experience?
   • What do you think analysts actually do day to day?
   • Which group do you want and why?

   Reported by candidates at Goldman Sachs (Investment Banking, New York, 2026); Citi (Investment Banking, San Francisco, 2025); Truist Securities (Investment Banking, Charlotte, 2026); Deutsche Bank (Investment Banking, London, 2022); Rothschild & Co (Investment Banking, London, 2025). Source: Wall Street Oasis.

7. 097What do analysts actually do day to day, beyond financial modelling?FitIntermediatetechnicalRothschild & CoInvestment Banking · Exeter · 2026

   Say this

   Most of it is not modelling. It is building and formatting pitch materials, running diligence and data rooms, coordinating between lawyers, accountants and the client, and doing the unglamorous version control that keeps a live process from falling over.

   Then walk it

   1. Materials: pitchbooks, management presentations, information memoranda, board decks. Formatting to house standard, and endless turns of comments from three levels of seniority.
   2. Research and diligence: comps and precedent screens, industry reads, buyer lists, and managing the data room and the question log on a live deal.
   3. Process management: scheduling, tracking who has signed which NDA, chasing the lawyers and accountants, and keeping the working group list current. On a live deal this is most of the job.
   4. Then the modelling, which is the part everyone prepares for and probably a fifth of the time.
   5. And the part candidates never mention: quality control. Checking that every number in a 60-page deck ties to the model, and that the version being printed is the current one. That is where analysts actually get judged.
   6. Saying this clearly signals that you know what you are signing up for, which is exactly why the question gets asked.

   Where candidates lose it

   Describing the job as building models and advising CEOs. It is not, for the first two years, and an interviewer who does the job will hear the fantasy immediately. Naming the administrative reality without sounding unwilling to do it is the winning move.

   Expect next

   • Does that sound appealing to you?
   • How do you handle repetitive work?
   • Tell me about a time you fell behind schedule.

   Reported by candidates at Rothschild & Co (Investment Banking, Exeter, 2026). Source: Wall Street Oasis.

8. 098Would you deliver an analysis on time with 90 percent confidence in the numbers, or delay it to get to 100 percent?FitHardsuperdayGoldman SachsInvestment Banking · New York · 2025

   Say this

   Deliver on time, and flag exactly which parts I am not confident in. In banking a late answer is often useless, but an unqualified wrong number is worse. The professional move is to hit the deadline with the uncertainty labelled.

   Then walk it

   1. Start by rejecting the premise that those are the only two options. The third path is to deliver on time and say precisely where the 10 percent of doubt sits.
   2. Then the judgement: it depends on what the number is for. A directional figure for an internal discussion can go out at 90 percent. A number going into a fairness opinion, a public document or a signed agreement cannot.
   3. So I would triage: is this decision-critical and irreversible, or is it an input to a conversation that will iterate?
   4. And the escalation point, which is what they are really testing: I would tell my associate before the deadline, not after, so they can decide whether to take the risk or buy more time from the client. Hiding the uncertainty is the only genuinely wrong answer.
   5. Then close with the practical habit: I would send it with a short note saying which two assumptions are soft and what I would need to firm them up.

   Where candidates lose it

   Picking one horn of the dilemma and defending it absolutely. Both extremes are wrong. The answer is on time, with the uncertainty disclosed, escalated early, and the threshold set by what the number will be used for.

   Expect next

   • What if your associate tells you to send it without the caveat?
   • Tell me about a time you were in an ethical dilemma.
   • Tell me about a time you fell behind schedule.

   Reported by candidates at Goldman Sachs (Investment Banking, New York, 2025). Source: Wall Street Oasis.

9. 099Tell me about a time you faced an ethical dilemma, or saw someone do something you thought was wrong.FitIntermediatesuperdayBank of AmericaInvestment Banking · New York · 2025J.P. MorganAsset Management · New York · 2026SSState StreetGlobal Data · Boston · 2024

   Say this

   Use a real, small, resolved example. Something where you noticed a problem, raised it through the right channel, and it was fixed. Scale does not matter; the pattern does.

   Then walk it

   1. Pick something genuinely ambiguous but low-stakes: a teammate misrepresenting data in a group project, an internship colleague using an outdated figure in a client-facing document, an expenses issue on a society committee.
   2. Structure it as situation, what made it a dilemma, what you actually did, and the outcome. Fifteen seconds on the setup, most of the time on the action.
   3. Show that you went to the person first before escalating. Interviewers in regulated firms want to see proportionality, not someone who immediately reports a colleague.
   4. Be specific about the discomfort. 'I did not want to accuse him, so I asked him where the number came from' is credible. Certainty is not.
   5. Avoid two failure modes: a story where you did nothing, and a story so grave that it raises questions about the environments you have been in. And never name a real employer's confidential matter, because how you handle that in the interview is itself the test.

   Where candidates lose it

   Claiming you have never faced one. That reads as either no self-awareness or no willingness to engage. Equally bad is a story where you stayed silent and rationalised it. Have one prepared, rehearsed, and resolved.

   Expect next

   • What would you have done if raising it had cost you the grade or the offer?
   • Tell me about a time you made a difficult decision.
   • Tell me about a time you disagreed with a manager.

   Reported by candidates at Bank of America (Investment Banking, New York, 2025); J.P. Morgan (Asset Management, New York, 2026); State Street (Global Data, Boston, 2024). Source: Wall Street Oasis.

10. 100Why should we take you over the other candidates from your university with exactly the same experience?FitHardsuperdayRothschild & CoInvestment Banking · Milan · 2025Houlihan LokeyInvestment Banking · New York · 2026MorningstarGeneralist · Chicago · 2024

    Say this

    Do not claim to be smarter or more driven, because everyone in the room says that. Name one specific, verifiable thing you have that they probably do not, and connect it to the work.

    Then walk it

    1. The honest framing first: on paper we are similar, and I would not pretend otherwise. So the answer has to be something specific rather than an adjective.
    2. Then the differentiator, and it should be concrete. Depth in one sector nobody else in the class has looked at. A language and a market. A technical skill like Python or SQL you have actually used on a dataset. Having run something with real accountability and real money.
    3. Then tie it to their business, not to your CV. Something like: your industrials team does a lot of cross-border work in Italy, and I can read Italian filings and speak to a management team without an interpreter. That is useful on day one.
    4. Then the evidence, in one line, because the claim is worthless unless it is checkable.
    5. And avoid the two failure modes: listing adjectives, which is unfalsifiable and forgettable, or disparaging other candidates, which reads badly in a business where you will spend your life in a small team.

    Where candidates lose it

    Answering with 'work ethic' and 'passion'. Every candidate says both and neither can be verified. Pick a specific, checkable capability and connect it to something their desk actually does. Specificity is the entire answer.

    Expect next

    • What is something about you that is not on your CV?
    • Why this group, and what do you add that someone else cannot?
    • What is one thing you wish had gone differently today?

    Reported by candidates at Rothschild & Co (Investment Banking, Milan, 2025); Houlihan Lokey (Investment Banking, New York, 2026); Morningstar (Generalist, Chicago, 2024). Source: Wall Street Oasis.

Firm tags come from public, anonymous candidate reports on Wall Street Oasis: strong signal, not sworn testimony. Firms are named as the places a question was reported, not as partners of Fin Maverick. Answers are written for this page to show how to think out loud; they are not scripts to recite.