Answer:
Step-by-step explanation:
The total count of laptops, N = 20
Defective laptops, n = 3
The school is purchasing 2 laptops
Case 1:
Both purchased laptops are non-defective
Probability of selecting 2 non-defective laptops
The count of non-defective laptops equals 20 - 3 = 17
Overall laptop count = 20
Probability, P = 17/20 = 0.85
Case 2:
One laptop is found defective
The probability of choosing 1 defective and 1 non-defective laptop
P' = 3/20 x 17/19 = 0.134
Case 3:
Both laptops are defective
Choosing 2 laptops from 3 = 3 C 2 = 3
Selecting 2 from 20 = 20 C 2 = 190
The probability of selecting two defective laptops equals 3 / 190 = 0.0158
P'' =