Question

Two dice are thrown simultaneously. What is the probability that the sum of the numbers appearing on the dice is a prime number?

• A. \(\frac{5}{12}\)
• B. \(\frac{7}{12}\)
• C. \(\frac{1}{2}\)
• D. \(\frac{13}{36}\)
• E.

Hint:

To quickly find the number of ways to get a sum \(S\) on two dice:
• If \(S \le 7\), ways \(= S - 1\).
• If \(S > 7\), ways \(= 13 - S\). Using this: \(1(2) + 2(3) + 4(5) + 6(7) + 2(11) = 15\).

Answer 1

The Correct Option is A