Question

Two dice are tossed simultaneously. Then the probability that the total score is a prime number is:

• A. 1/12
• B. 5/12
• C. 7/12
• D. 1/2
• E. none

Answer 1

The correct option is B

5/12

Clearly, (S) = (6 x 6) = 36.

Let E = Event that the sum is a prime number.

Then E = { (1, 1), (1, 2), (1, 4), (1, 6), (2, 1), (2, 3), (2, 5), (3, 2), (3, 4), (4, 1), (4, 3),(5, 2), (5, 6), (6, 1), (6, 5) }

$\therefore$ (E) = 15.

So P(E) = $\frac{5}{12}$.