Question

In class of 720 sophmores 200 take French 300 take Math 350 take Science 150 take 2/3 subjects 100 take none. How many people take all 3 classes?

Answer 1

Answer: There are 20 people who take all 3 classes.

Explanation:

Since we have given that

Total number of sophmores = 720

Number of people who take French = 200

Number of people who take math = 300

Number of people who take Science = 350

Number of people who takes two out of three subjects = 150

Number of people who takes none = 100

So, Number of people who takes all 3 classes is given by

`n(all)=n(F)+n(M)+n(S)-n(two\ subjects)+n(three\ subjects)\\\\720=200+300+350-150+x\\\\720=700+x\\\\720-700=x\\\\20=x`

Hence, there are 20 people who take all 3 classes.