a is chosen from the set {1,2,3,4} and b is chosen from the set {5,6,7,8,9,10}. what is the probability that the product ab is a prime number
+37167 There are 4 x 6 = 24 possible combos of a and b
the only primes would be 1 * 5 1*7 two out of 24 = 1/12
