Question

A factory produces fuses, which are packaged in boxes of 22. Four fuses are selected at random from each box for inspection. The box is rejected if at least one of these four fuses is defective. What is the probability that a box containing two defective fuses will be rejected?

Answer 1

The probability of finding one of the two defective fuses is:

`(2C1*20C3)/(22C4)=0.3117`
The probability of finding 2 defective fuses is:
`(2C2*20C2)/(22C4)=0.026`
Therefore the probability of rejecting is 0.3117 + 0.026 = 0.3377.