Question

If a pair of dice are thrown, find the probability of getting a prime sum.

Answer 1

The favourable outcomes in this experiment are (1,1), (1,2), (2,1), (1,4), (2,3), (3,2), (4,1), (1,6), (2,5), (3,4), (4,3), (5,2), (6,1), (5,6) and (6,5). That is, 15 favourable outcomes out of a total of 36.
The probability is = $\frac{15}{36}$ = $\frac{5}{12}$