Question

A box contains four slips numbered 1, 3, 5, 7 and another box contains three slips numbered 2, 4, 6. If one slip is drawn from each box.
(i). What is the probability that the product of the numbers being a prime ?

Hint:

For a product of two integers to be prime, one of the integers must be 1 and the other must be a prime number. In this problem, we need to pick 1 from the first box and a prime number (2, 4, 6) from the second. The only prime in the second box is 2. So the only favorable pair is (1, 2). This logic helps find the answer quickly.

Answer 1