PRACTICE GUIDE MARSHALL WACE
Marshall Wace Quantitative Paper: what the test is, and how to train for it
The Marshall Wace quantitative paper screen is 14 questions in 120 minutes - about 8.6 minutes each - answered by typing the number, with no calculator. There is no negative marking, so leaving an item blank gains you nothing over guessing.
Where it sits: Quantitative paper. The practice sitting on this page runs the same item count, the same clock and the same marking rule, with questions generated by Outcry rather than taken from Marshall Wace.
Outcry is not affiliated with Marshall Wace 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 Marshall Wace’s own.
What it screens
A London-based global hedge fund known for TOPS, its systematic long/short equity platform.
- ✓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 Marshall Wace
This is the whole sitting rather than one section of it: 14 items in 120 minutes, on one clock.
You can return to earlier items within the section, so a first pass for the quick ones and a second for the rest is a workable plan.
The format
These are the numbers the Marshall Wace sitting on this site runs on, matching the format candidates report.
| Questions | 14 |
|---|---|
| Time | 120 minutes |
| Per question | 8.6 minutes |
| Negative marking | No |
| Answer style | Typed numeric answer, no calculator |
| Where it sits | Quantitative paper |
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 Marshall Wace’s.
Expected value and odds
Pricing a bet, converting between odds and probabilities, and deciding whether to take it.
Example
Roll 2 fair dice. Probability every die shows a six?
- 1/216
- 1/36
- 2/6
- 1/12
Answer 1/36
Independent rolls multiply: (1/6)^2 = 1/36.
Counting and combinatorics
Arrangements, selections and the complement trick that turns a hard count into an easy one.
Example
A drawer holds 11 fair test coins and one with heads on both faces. One is taken out at random and tossed repeatedly, coming up heads every time. How many heads in a row are needed before the probability that it is the two-headed one first reaches 0.98?
Answer 10
Posterior after h heads is 2^h/(2^h + 11), from prior odds 1 to 11 multiplied by a likelihood ratio of 2^h. Setting that at or above 0.98 gives 2^h >= 11 x 0.98/(1 - 0.98) = 539, so h = 10. Check: 9 heads gives 0.979, which is short, and 10 heads gives 0.9894. Each head is one doubling of the odds, so the count grows only with the log of the pile.
Distributions you should know cold
Binomial, geometric and uniform means and variances, applied rather than quoted.
Example
Two fair 6-sided dice are rolled out of sight. At least one shows a 6. What is the chance both do?
- 18.2%
- 2.8%
- 16.7%
- 9.1%
- 50%
Answer 9.1%
Outcomes with at least one 6 number 11, and exactly one of those has both, so 1/11 = 9.1%. The intuitive 1/6 answers the different question where a NAMED die shows a 6.
Estimation under uncertainty
A number nobody knows exactly, reasoned to the right order of magnitude out loud.
Example
Whole numbers are picked one at a time, and you get to keep picking. How many do you have to pick to be certain that two of them leave the same remainder when divided by 18?
Answer 19
The remainders are the 18 boxes, 0 through 17. Picking 18 numbers can dodge a repeat exactly once, by hitting every remainder, so 19 forces one. The same statement says two of the picks differ by a multiple of 18, which is how this argument usually turns up.
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%.
Symmetry arguments
Questions that collapse to one line once you notice the two cases are mirror images.
Example
A fair 10-sided die pays its face value, plus a bonus of 6 if it lands on 10. What is the expected payout?
Answer 6.1
The face averages 5.5 and the bonus adds 6/10 = 0.6, giving 6.1.
What a good score looks like
On a paper of 14 questions with no penalty for a wrong answer, the only thing an unanswered question can do is cost you. Probability rounds are usually marked as part of a wider battery, so a standalone threshold is rarely reported. Where candidates do describe one it clusters around getting two thirds of the items right, with the caveat that these sections are short enough that two mistakes move you a long way.
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.
- 03Sanity-check the magnitude before committing. A probability above one or an expectation outside the range of outcomes is a caught error, and these papers plant both as options.
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 Marshall Wace
Common questions
- Is the Marshall Wace quantitative paper test multiple choice?
- Typed numeric answer, no calculator. You type the number, so there is nothing to eliminate your way to.
- How long is the Marshall Wace quantitative paper test?
- 14 questions in 120 minutes, which is about 8.6 minutes each.
- Is there negative marking on the Marshall Wace quantitative paper test?
- No. A wrong answer costs nothing beyond the mark you would have earned, so leaving an item blank is never better than guessing at it.
- How do I practise for it free?
- Every drill linked on this page is free to play, with no account, inside a daily run cap. Questions are generated fresh each run, so there is nothing to memorise between attempts. The full Marshall Wace Invigilated Quant Paper sitting puts the sections back to back on one clock.