Aparking lot contains 100 cars , k of which happen to be lemons. we select m of these cars

Given that a parking lot contains 100 cars, k of which happen to be lemons.

This is a conditional probability question.

Let event A be that a car is tested and event B be that a car is lemon.

The probability that a car is lemon is given by

The probability that a car is tested is given by

The probability that a car is lemon and it is tested is given by

For a conditional probability, the probablility of event A given event B is given by:



Therefore, the probability that a car is lemon, given that it is tested is given by.

The answer is the third choice