Fast Quant Drill For Finance Talent
This conversation was generated using Cook'd AI's career assistant and reviewed by Fallon Han from our editorial team for accuracy.
I need a high-speed technical session. I'm a final-year math student in Canada on a work permit, and I'm targeting quant trading boutiques. Please run a fast probability and mental math drill that adapts to my answers and tells me how I did on speed, accuracy, and composure.
Understood. I will keep this tight, realistic, and under pressure. We will use short-answer questions only, and I will score each response on accuracy, speed, and clarity.
Rules:
1. Answer with just the final result unless I ask for reasoning.
2. If you get stuck, say so quickly rather than freezing.
3. I will increase difficulty if you are fast and clean, or simplify if you miss basics.
Round 1, warm-up but timed:
A fair coin is flipped 3 times.
What is the probability of getting exactly 2 heads?
Also tell me how long it took you in seconds.
3/8. About 8 seconds.
Good start. Accuracy is correct. Speed is acceptable for a warm-up, but in a boutique interview I would want that under 5 seconds.
Score so far:
Accuracy: 1/1
Speed: 6/10
Composure: 8/10
Round 2, slightly faster:
A bag has 5 red and 3 blue balls. You draw 2 without replacement.
What is the probability both are red?
Give only the answer and your time.
5/14. 11 seconds.
Correct again, but your pace dropped. The structure should be immediate: 5/8 times 4/7 = 5/14.
Interim evaluation:
Accuracy is strong on basic probability.
Your speed is drifting above target for quant screening pace.
Composure is still good, but you are thinking aloud internally, which can slow you down.
Round 3, mental math under time pressure:
Without using a calculator, estimate 19.8 times 5.1.
Then give me the exact answer if you can do it quickly.
About 100.98. Exact is 100.98, and it took me 6 seconds.
Excellent. That is clean and fast.
That answer shows good numerical control and no panic under pressure.
Score update:
Accuracy: 3/3
Speed: 7/10
Composure: 9/10
Round 4, harder probability:
A trading signal is correct 60 percent of the time. You make 4 independent trades.
What is the probability exactly 3 of them are correct?
Keep it compact.
4 times 0.6 cubed times 0.4, so 0.3456.
Correct. You used the right binomial form and got to the result quickly.
One correction for interview polish: say the expression out loud more cleanly as 4 choose 3 times 0.6 to the 3 times 0.4 to the 1. Your math was right, but the verbal packaging matters in live interviews.
Final round, pressure test:
If you can answer in under 7 seconds, do it.
What is 17 percent of 260?
Then I will give you a final report on accuracy, speed, and whether you looked recruitable for a quant trading boutique.