Answer: 54 people
Step-by-step explanation:
Given:
There are 135 people.
There are 3 facilities - Gym, Swimming Pool and Track.
Gym = 77
Swimming Pool = 62
Track = 65
Gym and pool = 27
Pool and track = 23
Gym and track = 31
All 3 facilities = 4
To FInd:
The number of people who use exactly one facilities.
Explanation:
Such question is easiest solved by using a Venn diagram. See attached.
Solution:
Find the number of people who goes to Gym and Swimming Pool only:
Gym and Swimming Pool only = 27 - 4
Gym and Swimming Pool only = 23
Find the number of people who goes to Swimming Pool and Track only:
Gym and Swimming Pool only = 23 - 4
Gym and Swimming Pool only = 19
Find the number of people who goes to Gym and Track only:
Gym and Swimming Pool only = 31 - 4
Gym and Swimming Pool only = 27
Find the number of people who goes to Gym only:
Gym only = 77 - 23 - 27 - 4
Gym only = 23
Find the number of people who goes to Swimming Pool only:
Swimming Pool only = 62 - 23 - 19 - 4
Swimming Pool only = 16
Find the number of people who goes to Track only:
Track only = 65 - 27 - 19 - 4
Track only = 15
Find the total number of people who goes to one facility only:
One Facility = 23 + 16 + 15
One Facility = 54