Question

Assume that the box contains 2 defective widgets and18 acceptable widgets. There are 5 inspectors, each of whom selects a widget from the box at random, inspects it, and then replaces it in the box. Each inspector makes his or her inspection at a different time.
What is the probability that at least one inspector will find a defective
widget?

Answer 1

Probability that any one inspector finds a defective one is

1/9 and doesn't find one is 8/9 so it should be 1−(8/9)^5