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Counting & ProbabilitySuperchallengeConditional Probability, Independence & Bayes

Conditional Probability, Independence & Bayes · Superchallenge problem

For a positive integer nn, an integer XX is chosen uniformly at random from {1,2,…,n}\{1,2,\dots,n\}. Let AA be the event that XX is even and BB the event that XX is a multiple of 33. For how many nn with 1≤n≤1001\le n\le100 are AA and BB independent, that is, P(A∩B)=P(A) P(B)P(A\cap B)=P(A)\,P(B)?