There are 130 people in a sport centre. 61 people use the gym.
68 people use the swimming pool.
60 people use the track.
25 people use the gym and the pool.
30 people use the pool and the track.
19 people use the gym and the track.
6 people use all three facilities.
How many people didn't use any facilities?

With #! i’ve tried to figure it out but i can’t.

As part of an annual fundraiser to raise money for diabetes research, diane joined a bikeathon. the track she biked on was 1,920 yards long. diane biked 38.5 laps. her sponsors agreed to donate an amount of money for each mile she biked. how many miles did she bike? first fill in the blanks on the left side using the ratios shown. then write your answer. given ratios: 5280ft / 1 mi , 1 mi /5280 ft , 1,920 yards / 1 lap , 1 lap / 1,920 yards , 3 ft / 1 yard , 1 yard / 3 ft. blanks: 38.5 laps / 1 yard x (blank) x (blank) x (blank) = (blank) miles i'm really confused on how to do this, and the explanations aren't exactly . if you could walk me through how to do this, it would be greatly appreciated.

If the scale factor between two circles is 2x/5y what is the ratio of their areas?