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Prime-faced dice with a prime total

Question

Two fair dice each have the six smallest primes, 2,3,5,7,11,132,3,5,7,11,13, on their faces. Both are rolled. What is the probability that the sum of the two faces is itself a prime number?

Short answer

16\tfrac16. Two odd primes sum to an even number above 2, and 2+2=42+2=4, so a prime total needs exactly one die showing 2 and the other showing an odd prime qq with q+2q+2 prime. That works for q=3,5,11q=3,5,11, each in two orders, giving 66 of the 3636 outcomes.

Adapted from QuantQuestions.io; question and answer rewritten by SelfMadeQuant.com.

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