Question

accepted if a sample of 5 bolts taken from that batch contains no defective and rejected if the sample contaims 3 or more deféctives.In0.other cases, a second sample is taken.What is the probability that second sample is required?

Answer 1

According to question

20% bolts are defective

Thus probability of defective bolts = 20/100 = 1/5

Thus according to question

Probability that batch doesnt contain any defective bolt = 5/80

                                                                                       = 1/16

And

Probability that batch contains three defective balls = 3/20

Answer 2

hello mate here is your answer