Roulette with a respin before every trigger pull
Question
Two players take turns with a six-chamber revolver containing one bullet, but now the cylinder is spun again before every single pull. Should you go first or second, and what is your probability of being shot under each choice?
Short answer
Go second: you are shot with probability , versus going first. Each pull fires with probability , independently. The first player is shot with probability .
Adapted from Zhou, A Practical Guide to Quantitative Finance Interviews, sec. 4.3 Conditional Probability and Bayes' Formula, 'Russian roulette II', p.81; question and answer rewritten by SelfMadeQuant.com.
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Open the worked solutionLessons behind this question
- Conditional Probability, Total Probability, and Bayes' Rule
- Worked Examples — Probability Trees, Monty Hall, and Bayesian Updating
- Series and the Geometric Series: Partial Sums and Convergence
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