PRACTICE GUIDE MAKO
Mako Problem-solving Test Practice
Outcry’s Mako problem-solving test practice section has 28 questions in 30 minutes. These numbers describe the linked mock; the source check below distinguishes published details from practice settings.
Outcry runs 37 questions in 15 minutes, then 28 in 30 minutes. Those counts, clocks and marking are practice settings.
Outcry is not affiliated with Mako 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 Mako’s own.
What it screens
A derivatives market maker founded in London, trading options and futures across global exchanges.
- ✓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 Mako
Mako’s cited graduate engineering application-process block lists aptitude and problem-solving tests. It does not confirm the trading mock’s exact format or separately numbered trading rounds.
Practice stage: Assessment practice · aptitude + problem solving. Outcry runs 37 questions in 15 minutes, then 28 in 30 minutes. Those counts, clocks and marking are practice settings.
The format
These are the settings used by Outcry’s Mako practice sitting. They are not automatically the employer’s published format; see the linked assessment’s source check.
| Questions | 28 |
|---|---|
| Time | 30 minutes |
| Per question | 64 seconds |
| Negative marking | No |
| Answer style | Multiple choice |
| Where it sits | Assessment practice · aptitude + problem solving |
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 Mako’s.
Expected value and odds
Pricing a bet, converting between odds and probabilities, and deciding whether to take it.
Example
You roll a fair die 3 times. Probability of at least one six?
- 50%
- 32.1%
- 42.1%
- 0.5%
Answer 42.1%
Complement: 1 − (5/6)^3 = 42.1%. Adding 1/6 each time double-counts.
Conditional probability
Bayes' rule in disguise: a test result, a signal, a drawn card, and what it implies.
Example
A strategy's daily returns over n days average x̄ with sample standard deviation s. Which statistic tests whether the true mean return is zero?
- x̄ / (s/√n)
- x̄·√n / s²
- (x̄ − s) / n
- x̄ / s
Answer x̄ / (s/√n)
The one-sample t-statistic divides the observed mean by its standard error s/√n. Dividing by s alone ignores how the estimate sharpens with n.
Distributions you should know cold
Binomial, geometric and uniform means and variances, applied rather than quoted.
Example
Two return series correlate at 0.5. What share of the variance in one is explained by a linear fit on the other?
- 100%
- 75%
- 25%
- 70.7%
- 50%
Answer 25%
R² is the square of the correlation: 0.5² = 0.25, so 25%.
Ranking outcomes
Ordering several events by likelihood, where only the exact order scores.
Example
A. a queen from a full deck B. two dice summing to 6 C. exactly two tails in four coin flips
Rank most likely to least likely:
- C > B > A
- A > C > B
- B > C > A
- A > B > C
Answer C > B > A
A: 7.7% · B: 13.9% · C: 37.5%
Waiting times and repeated trials
How long until the first success, and why the answer is rarely the average you expected.
Example 1
How many digits does 50! have?
Answer 65
Stirling: log10(50!) ≈ 50·log10(50/e) + ½·log10(2π·50) = 63.23 + 1.25 = 64.48, so 65 digits.
Example 2
How many observations are needed for a 95% confidence interval of half-width 2.5, when the standard deviation is 25?
Answer 385
n = (1.96σ/w)². Call it 2: (2 × 25/2.5)² = 400, which overshoots by 4%.
Example 3
A trading floor has 40 people on it. What is the chance that at least two share a birthday, as a percentage?
Answer 89
There are C(40,2) = 780 pairs, each matching with probability 1/365. P(none) ≈ e^−2.14 ≈ 0.12, so about 88%.
Reading the question exactly
At least, exactly, and given that - the three phrases that change the answer entirely.
Example
A puts in 3,000 for 4 months and B puts in 13,000 for 9 months. They clear 33,000 of profit. What is A's share?
- 16,500
- 10,153.85
- 6,187.5
- 3,069.77
Answer 3,069.77
Profit follows capital multiplied by time. A contributes 3,000 x 4 = 12,000 and B contributes 13,000 x 9 = 117,000, so A takes 12,000 / 129,000 of 33,000 = 3,069.77.
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.
- 03Work the complement first whenever the question says at least or at most. It is usually the shorter route and it is almost always the intended one.
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 Mako
Common questions
- Is this Mako’s official problem-solving test test?
- No. Outcry generates its own questions. Mako’s cited graduate engineering application-process block lists aptitude and problem-solving tests. It does not confirm the trading mock’s exact format or separately numbered trading rounds. Outcry runs 37 questions in 15 minutes, then 28 in 30 minutes. Those counts, clocks and marking are practice settings.
- How long is this problem-solving test practice section?
- 28 questions in 30 minutes in the Outcry mock. These are practice settings unless the source check explicitly confirms them.
- How is the practice marked?
- Correct answers earn 1 mark unless the question states another weight. Wrong answers lose 0; 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.