Question

There are 130 people in a sport centre. 73 people use the gym. 62 people use the swimming pool. 58 people use the track. 22 people use the gym and the pool. 29 people use the pool and the track. 25 people use the gym and the track. 11 people use all three facilities. Given that a randomly selected person uses at least two facilities, what is the probability they use all the facilities?

Answer 1

`(11)/(87)`

Explanation:

Total number of people = 130

Number of people who use the gym = 73

Number of people who use the pool = 62

Number of people who use the track = 58

Number of people who use the gym and the pool = 22

Number of people who use the pool and the track = 29

Number of people who use the gym and the track = 25

Number of people who use all three facilities = 11

Total number of people who use at least two facilities = 22 + 29 + 25 + 11 = 87

The probability that the randomly selected person uses all three facilities = number of those who use all three facilities ÷ total number of people who use at least two facilities.

==> 11 ÷ 87

==>
`(11)/(87)`