a is chosen from the set {1,2,3,4}, and b is chosen from the set {5,6,7,8,9}. What is the probability that the product ab is a prime number?

hehehehe Aug 18, 2020

#1**0 **

Looks like 4 x 5 = 20 possibilities

only primes would be the primes in set 2 x one ===== 5 0r 7

2 out of 20 = 1/10 = .1 or 10%

ElectricPavlov Aug 18, 2020