Question

There are 135 people in a sport centre. 73 people use the gym. 59 people use the swimming pool. 31 people use the track. 19 people use the gym and the pool. 9 people use the pool and the track. 16 people use the gym and the track. 4 people use all three facilities. Given that a randomly selected person uses the gym and the track, what is the probability they do not use the swimming pool?

Answer 1

The probability that a person who uses the gym and the track does not use the swimming pool is 3/4.

Step-by-step explanation:

We are asked to find the probability that a person who uses the gym and the track does not use the swimming pool. The number of people who use both the gym and the track is 16. Among these, 4 also use the pool, which means that 16 - 4 = 12 people use just the gym and the track, and not the pool. The probability that a randomly selected person who uses the gym and the track does not use the pool is calculated as the number of gym-and-track users who don't use the pool divided by the total number of gym-and-track users, which is 12/16 or 3/4.