AMC 10B 2019 #17 — Ball Toss into Bins Probability
1900SpecialistCombinatoricsProbability
AMC 10B · 2019 · Problem 17
A red ball and a green ball are randomly and independently tossed into bins numbered with positive integers so that for each ball, the probability that it is tossed into bin $k$ is $2^{-k}$ for $k=1,2,3,\ldots.$ What is the probability that the red ball is tossed into a higher-numbered bin than the green ball?