Question

a bin contains 78 light bulbs of which four are defective. If five are randomly selected from the bin without replacement, find the probability that all five are not defective.

Answer 1

0.7630

Explanation:

Probaility of defective = 4/78

Probability of NOT defective = 1 - 4/78 = 74/78

Note: probability of NOT A = 1 - probability of A

Since without replacement, we need to consider that with each turn, 1 goes down from total and we multiply all the 5 outcomes, hence:

Probability 5 not defective =
`(74)/(78)*(73)/(77)*(72)/(76)*(71)/(75)*(70)/(74)=0.7630`

THis is the answer, 0.7630