In: Statistics and Probability
A used car lot has 150 cars, 90 of the cars are black and 60 cars are blue. What is the probability of 2 blue cars being test drove back to back; assuming the first car is purchased?
What is the probability of 2 blue cars being test drove back to back; assuming the first car was not purchased?
We have total number of cars as 150. Among that 90 are black and 60 are blue.
So clearly, we have
Now we have 2 situations.
Situation 1: Back to back test drive of 2 blue cars given that the first car is purchased.
Now since the first blue car is sold, when a customer comes to lot for test drive, there is only 59 blue cars remaining. Also the total number of cars in the lot reduces to 149. Hence,
Probability of 2 blue cars being test drove back to back; assuming the first car is purchased is given by,
Situation 2 :Two blue cars being test drove back to back; assuming the first car was not purchased
Now since the first blue car is not sold, when a customer comes to lot for test drive, there is still 60 blue cars remaining. Also the total number of cars in the lot remains to be 150. Hence,
Probability of 2 blue cars being test drove back to back; assuming the first car is purchased is givgen by,