Question

A box contains 45 cubes numbered 1-45. What is the probability of pulling out 2 primes in a row if the first one is. It replaced?

Answer 1

1/9

Explanation:

prime #'s between 1 and 45:

2,3,5,7,11,13,17,19,23,27,29,31,37,41,43

P(prime,prime) = 15/45 × 15/45 or 1/3 × 1/3