A survey of 100 people

Question

a survey of 100 persons at better widgets finds that 40 jog, 25 swim, 16 cycle, 15 both swim and jog, 10 swim and cycle, 8 jog and cycle, and 3 person do all three. how many people at better widgets do not take part in any of these three exercise program?

Answer 1

Add together the three activities: 40 + 25 + 16 = 81

Subtract 15, 10, and 8 so that all the people who do 2 things are only counted one time. 81 - 15 - 10 - 8 = 48

Subtract 3 twice so that they people who do all 3 things are only counted 1 time. 48 - 3 - 3 = 42.

100 - 42 = 58 people do not do any exercises.