In a sample of 20 wafers 4 are found to be defective. Two are selected at random from the sample.

In a sample of 20 wafers 4 are found to be defective. Two are selected at random from the sample.a) what is the probability that the second sample is defective given that the first sample was defective?b) what is the probability that the second sample is defective given that the first sample was not defective?what is the probability that the second sample is not defective given that the first sample was defective?

(GIVEN)(GIVEN)(The first one is defective. There are only 3 defective out of 19)(There are four defective left after picking the first one as non defective)(There are 19 pieces left after...