PRACTICE GUIDE D. E. SHAW
D. E. Shaw Aptitude Practice Test
Outcry’s D. E. Shaw aptitude practice section has 14 questions in 28 minutes. These numbers describe the linked mock; the source check below distinguishes published details from practice settings.
This India-campus-inspired mock uses 95 minutes, four sections and 138 available marks. Counts, section weights, clocks, deductions and JavaScript are Outcry settings unless confirmed by your invitation.
D. E. Shaw's own interviewing guide describes its US and UK quant process as interview-only, with no online assessment at all. This guide instead models the firm's India-campus screen, which does run one - so if you're interviewing for a US or UK quant role, this practice does not reflect what you'll actually sit.
Outcry is not affiliated with D. E. Shaw and has no access to their assessment content. This guide describes an assessment format that candidates report publicly; the questions here are generated by Outcry and are not D. E. Shaw’s own.
What it screens
A quantitative investment firm based in New York, among the largest and longest-running in the industry.
- ✓Expected value computed fast and used to make a decision
- ✓Conditional probability and Bayes updates without formal notation
- ✓Ranking likelihoods rather than computing them exactly
- ✓Fermi estimation: decomposing an impossible question into three easy ones
Where it sits at D. E. Shaw
D. E. Shaw’s public interviewing guide describes typical interviews and relevant mathematical/computing skills. It does not establish this exact India campus test or rule out assessments in other regions.
Practice stage: India campus practice · current format unconfirmed. This India-campus-inspired mock uses 95 minutes, four sections and 138 available marks. Counts, section weights, clocks, deductions and JavaScript are Outcry settings unless confirmed by your invitation.
The format
These are the settings used by Outcry’s D. E. Shaw practice sitting. They are not automatically the employer’s published format; see the linked assessment’s source check.
| Questions | 14 |
|---|---|
| Time | 28 minutes |
| Per question | 2 minutes |
| Negative marking | Yes - a wrong answer costs a mark |
| Answer style | Multiple choice |
| Where it sits | India campus practice · current format unconfirmed |
What it tests, with a worked example
Every example below is generated by Outcry, drawn from the same question generators the timed drills run. None of them is D. E. Shaw’s.
Conditional probability
Bayes' rule in disguise: a test result, a signal, a drawn card, and what it implies.
Example
A token starts at position 1 on the integers 0 to 4. Each step it moves left or right with probability 1/2, and positions 0 and 4 absorb. What is the expected number of steps until absorption?
- 3
- 5
- 4
- 6
Answer 3
E[steps] from i is i(N−i) - the martingale Sₙ²−n stopped at the boundary: 1·3 = 3.
Distributions you should know cold
Binomial, geometric and uniform means and variances, applied rather than quoted.
Example
1% of a population carries a trait. A screen flags 95% of carriers and wrongly flags 2% of non-carriers. Someone is flagged. What is the chance they carry it?
- 95%
- 98%
- 1%
- 32.4%
- 67.6%
Answer 32.4%
True flags are 1 × 0.95 = 0.95% of everyone, false flags 99 × 0.02 = 1.98%. The share that is real is 0.95/(0.95 + 1.98) = 32.4%.
Estimation under uncertainty
A number nobody knows exactly, reasoned to the right order of magnitude out loud.
Example
An 8 by 10 grid of squares has the two squares at opposite ends of one diagonal cut out, leaving 78. A domino covers exactly two squares that share an edge. What is the largest number of dominoes that fit without overlapping or hanging off?
Answer 38
Colour the grid like a chessboard. A domino always takes one square of each colour. Opposite corners of a diagonal share a colour, so cutting them leaves 38 of one colour and 40 of the other. The smaller pile caps the dominoes at 38, and that many really do fit, so the cap is the answer. The counting argument, not a picture, is what settles it.
Ranking outcomes
Ordering several events by likelihood, where only the exact order scores.
Example
A. no heads in five coin flips B. the ace of spades from a full deck C. two dice both showing six
Rank most likely to least likely:
- C > A > B
- A > C > B
- C > B > A
- A > B > C
Answer A > C > B
A: 3.1% · B: 1.9% · C: 2.8%
Waiting times and repeated trials
How long until the first success, and why the answer is rarely the average you expected.
Example
A quote engine throws an average of 1.9 errors an hour, Poisson. What is the chance of an error-free hour, as a percentage?
Answer 15
P(0) = e^−1.9 = e^−1 × e^−0.9 ≈ 0.3679 × 0.41 ≈ 0.1496, so about 15%.
Reading the question exactly
At least, exactly, and given that - the three phrases that change the answer entirely.
Example
Revenue by division, $m Division 2016 2017 2018 2019 Rates 140 420 430 325 Macro 390 325 335 300 Credit 305 160 230 480 Equities 175 195 155 225
What was Rates average annual revenue across the four years shown?
- 1315
- 285
- 328.75
- 325
Answer 328.75
140 + 420 + 430 + 325 = 1315, over four years that is 328.75. The midpoint of the highest and lowest, 285, is not the mean.
What a good score looks like
Use this mock’s score and worked review to identify skills to practise. No Outcry score guarantees a pass or a hiring outcome; a current employer threshold for this practice paper has not been verified.
How to train for it
- 01Work the standard results until they are recall, not derivation: complement, conditional, binomial mean and variance, geometric expectation.
- 02Practise setting up before calculating. Most wrong answers on these are a correct calculation of the wrong quantity.
- 03Do them timed. A probability question you can solve in four minutes and the paper gives you ninety seconds for is a question you cannot solve.
TRAIN IT HERE
The drills that match each section
Likelihood Ranking
Order events from most to least likely - the exact screen-question format.
Fermi Estimation
Piano tuners in Chicago, atoms in a body - scored on order of magnitude.
Quitters Never Lose
A casino stopping-strategy game that is secretly a martingale lesson.
Tail Risk
Rare events and fat tails, and what they do to a plain expected-value estimate.
SIT THE FULL BATTERY
All the sections back to back on one clock, marked the way the real screen marks them, with a by-skill breakdown at the end. Included with any pass.
Also reported at D. E. Shaw
Common questions
- Is this D. E. Shaw’s official aptitude test?
- No. Outcry generates its own questions. D. E. Shaw’s public interviewing guide describes typical interviews and relevant mathematical/computing skills. It does not establish this exact India campus test or rule out assessments in other regions. This India-campus-inspired mock uses 95 minutes, four sections and 138 available marks. Counts, section weights, clocks, deductions and JavaScript are Outcry settings unless confirmed by your invitation.
- How long is this aptitude practice section?
- 14 questions in 28 minutes in the Outcry mock. These are practice settings unless the source check explicitly confirms them.
- How is the practice marked?
- Correct answers earn 3 marks unless the question states another weight. Wrong answers lose 1; unanswered items lose 0, including timeouts. These rules apply to this mock.
- Where can I check the employer’s process?
- See the public source check on the linked assessment. Your role-specific invitation governs the actual format, permitted tools and scoring.