Three six-sided dice are rolled. Find the probability that the product of three numbers rolled is a prime number.
By definition of a prime, the only possible products that result in a prime require two of the dice to be 1 and the other a prime. So the possibilities are :
1 1 2, 1 2 1, 2 1 1
1 1 3, 1 3 1, 3 1 1
1 1 5, 1 5 1, 5 1 1
9 possibilities out of a total of 216 possible throws. So probability = 9/216