Expected Value Coin Games Interview Questions
Expected value coin games interview prep for fixed flips, waiting times, streak payoffs, geometric patterns, and independence mistakes.
Candidates practicing repeated trials, streaks, and payoff games.
Fixed-flip games
For a fixed number of flips, define the payoff for each count, streak, or event and average over the distribution.
Waiting-time games
If the payoff depends on time until heads or a pattern appears, geometric or state-based reasoning may be needed.
Concrete example
If a fair coin game pays 1 dollar for each head in four flips, the expected payoff is 4 x 1/2 = 2 dollars by linearity.
Streak payoffs
Streak games are usually not solved by treating streak events as independent. Use states or complements when overlap matters.
Fair price
Once expected payoff is computed, a fair entry price in the toy model is that expected payoff.
Common mistakes
Candidates often confuse number of heads with time until a head. Fixed-count and waiting-time setups use different distributions.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.