There are 135 people in a sport centre. 73 people use the gym. 73 people use the swimming pool. 67 people use the track. 36 people use the gym and the pool. 35 people use the pool and the track. 32 people use the gym and the track. 14 people use all three facilities. A person is selected at random. What is the probability that this person doesn't use any facility?

P = 11/135 = 0.0815

Step-by-step explanation:

we can said that:

14 people use all three facilities18 people use just gym and track (32 people use the gym and the track less the 14 people that use all three facilities)21 people use just pool and track (35 people use the pool and the track less the 14 people that use all three facilities)22 people use just gym and pool (36 people use the gym and the pool less the 14 people that use all three facilities)14 people use just the track (67 people use the track less the 18 people that use just the gym and the track, the 21 people that use just the pool and the track and 14 people that use all three facilities)16 people use just the pool (73 people use the swimming pool less the  the 21 people that use just the pool and the track, the 22 people that use just the gym and the pool and 14 people that use all three facilities)19 people use just the gym (73 people use the gym less the 18 people that use just the gym and the track, the 22 people that use just the gym and the pool and 14 people that use all three facilities)

So, there are 124 people that use the gym, the pool or the track. This is calculated using the information above as:

14 + 18 + 21 + 22 + 14 + 16 + 19 = 124

Finally, there are 11 ( 135 - 124 = 11 ) people that don't use any facility, so the probability that a person doesn't use any facility is:

P = 11/135 = 0.0815