Question

A factory received a shipment of 48 generators, and the vendor who sold the items knows there are 8 generators in the shipment that are defective. Before the receiving foreman accepts the delivery, he samples the shipment, and if too many of the generators in the sample are defective, he will refuse the shipment.

For each of the following, give your responses as reduced fractions.

If a sample of 8 generators is selected, find the probability that all in the sample are defective.



If a sample of 8 generators is selected, find the probability that none in the sample are defective.

Answer 1

Answer: The probability that all generators in a sample of 8 are defective can be calculated by finding the number of ways that 8 defective generators can be selected out of 48 total generators, divided by the total number of ways that any 8 generators can be selected out of 48 total generators.

The number of ways to select 8 defective generators out of 48 total generators is:

C(8,8)*C(40,0) = 1

The total number of ways to select 8 generators out of 48 total generators is:

C(48,8) = 1,907,725

The probability that all generators in a sample of 8 are defective is:

1/1,907,725

If a sample of 8 generators is selected, find the probability that none in the sample are defective.

The number of ways to select 8 non-defective generators out of 48 total generators is:

C(40,8) = 45,765

The total number of ways to select 8 generators out of 48 total generators is:

C(48,8) = 1,907,725

The probability that none in the sample are defective is:

45,765/1,907,725

Both of these are reduced fraction.