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A three-digit integer contains one of each of the digits $1,3$ , and $5$ . What is the probability that the integer is divisible by $5$ ? (2009 AMC 8 Problem, Question \#13) 
Overseas Competition->Knowledge Point->Counting Modules
The three digit numbers are $135,153,351,315,513,531$. The numbers that end in 5 are divisible are 5 , and the probability of choosing those numbers is (B) $\frac{1}{3}$. 