Compute probability match lasts 5 games | Waymo Interview Question
Compute probability match lasts 5 games
Quick Overview
This question evaluates understanding of discrete probability, sequential best-of-n match modeling, Monte Carlo simulation for probability estimation, and interval estimation for proportions.
Waymo
Nov 11, 2025, 12:00 AM
Data Scientist
Technical Screen
Statistics & Math
12
0
Two players play independent games of table tennis.
Player A wins each game with probability
p
(constant across games).
They play a
best-of-5
match (first to 3 wins).
Let
X
be the
number of games played
until the match ends (so
X∈{3,4,5}
).
Tasks
Compute
θ=Pr(X=5)
.
Write a simulation (Monte Carlo) approach to estimate
θ
.
Follow-up: given
M
simulated matches, how would you build a
confidence interval
for
θ
?