Jane Street

Interview Question

Trader Interview

Jane Street

I flip four coins and give you a dollar for each head. After all four coins are flipped, you may choose to re-flip one coin that landed tails. What is the expected value of this game?

Unlock the Full Solution

Enter your email to get instant access to the complete solution, explanation, and similar practice problems.

Insights on 100+ quant firms, understand where to apply, and maximize your chances.

Get the official 2025 QB Quant Firm Tier List

Check your email inbox — you should get the interview in 1-2 minutes!