Question

Please explain the answer and how to get the answer?

50 people each did one activity at a sports centre.
Some of the people went swimming.
Some of the people played squash.
The rest of the people used the gym.
21 of the people were female.
6 of the 8 people who played squash were male.
18 of the people used the gym.
9 males went swimming.
Work out the number of females who used the gym.

Answer 1

so this needs to be taken step by step
21 total females
29 males
2 females, 6 males were playing squash
19 females, 23 males for gym/swimming
9 males went swimming
19 females and 12 males
12 males are in the gym and a total of 18 people using the gym
6 females were using the gym