Question

) A bin contains 60 light bulbs of which 5 are defective. If 4 light bulbs are randomly selected from the bin with replacement, find the probability that all the bulbs selected are good ones. Round to the nearest thousandth if necessary

Answer 1

0.706

Explanation:

In this question, we are asked to calculate the probability that if 4 light bulbs are selected out of a total of 60, with 5 defective ones, all are good.

Firstly we need to find the probability of selecting a bulb that is not defective. Let’s call this P(g).

Since 5 are defective, it means 60-5 = 55 bulbs are not defective.

The probability of selecting a bulb not defective would be 55/60 = 11/12

Now, four are selected with claims that non are defective, the probability here would thus be 11/12 * 11/12 * 11/12 * 11/12 = 0.706066743827

To the nearest thousandth, we have 0.706