Expected Value quant interview questions

Expected value questions are among the most common in quant trading interviews because they mirror real trading decisions: what is a game worth, and should you play it? You will need linearity of expectation, indicator variables, conditioning on the first step, stopping rules and optimal strategies for dice, card and coin games. Interviewers often follow up by changing the payoff or letting you re-roll, so understanding why a method works matters more than recalling a number. The problems below range from one-line linearity tricks to multi-stage games with optimal stopping and variance follow-ups. Every free problem includes hints and a full worked solution, written to show the reasoning a strong candidate would say out loud, so you can build speed and confidence for market-facing interviews.