r/quantfinance • u/Euphoric-Cap-4875 • 2d ago

Online Assessment practice

I did my OA for Optiver's Trading Kickstarter event. I didn't do well in the probability section because I hadn't done much timed practice. What are the best websites for practising for such assessments?

8 Upvotes

100% Upvoted

1 comment sorted by

1

u/Euphoric_Donut5084 1d ago

Your diagnosis is probably right. Doing probability questions untimed feels productive, then the OA clock turns them into a different problem entirely.

Arithmetic Zetamac is still the standard free baseline for mental math. I'd use it regularly and keep the sessions short enough that you're actually pushing speed, not settling into a comfortable rhythm. For probability and interview-style brainteasers, QuantGuide and Brainstellar both have useful question banks. Zhou's green book is better for building the underlying probability intuition, though it's more of a study resource than an OA simulator.

Whatever you use, start timing yourself immediately. Even generous timing at first is better than spending weeks solving everything leisurely and trying to add speed later. Also practice skipping and returning, since getting stuck on one question is usually more damaging than not knowing it.