Of the items manufactured by a certain process, 20% are defective. Of the defective items, 60% can be repaired. a. Find the probability that a randomly chosen item is defective and cannot be repaired. b. Find the probability that exactly 2 of 20 randomly chosen items are defective and cannot be repaired.

Respuesta :

Answer:

a) 0.08

b) 0.157

Step-by-step explanation:

a) P(defective) = 0.2

P(no repair) = 1 - 0.6 = 0.4

P(no repair & defective)

= 0.2×0.4 = 0.08

b) 20C2×(0.08)²×(0.92)^18

= 0.156947197