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1981 AMC 12 Question 26

AMC12 · 1981 AMC 12

Question 26

Alice, Bob, and Carol repeatedly take turns tossing a die. Alice begins; Bob always follows Alice; Carol always follows Bob; and Alice always follows Carol. Find the probability that Carol will be the first one to toss a six. (The probability of obtaining a six on any toss is $\frac16,$ independent of the outcome of any other toss.)
  1. $\frac13$
  2. $\frac29$
  3. $\frac5{18}$
  4. $\frac{25}{91}$
  5. $\frac{36}{91}$