You roll three 3-sided fair dies, each numbered 1 to 3.
If the probability of having the sum of the three being an odd number is , where and are coprime positive integers , what is ?
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The three dies are generating 27 permutations, which can be considered as 27 consecutive numbers of a ternary number system. Since the first one 111 (equivalent to decimal 9+3+1 = 13) is an odd number, so will be the last, yielding 14 odd numbers (sums). This makes the probability of a odd sum = 14/27