of 50 students surveyed, 22 have a skateboard, and 18 have roller shoes. of those, 6 students have both. how many students have neither a skateboard nor roller shoes?

Answer 1

i don't know how to solve this
at first i thought it was 4 but in the back of the book it said the answer was 156 students and i don't know how it got the answer

Answer 2

16 students

Answer 3

If you add up 22+18, that's 40.
But, you counted the 6 who have both twice, so that leaves only 34.

So, of the 50 students, 34 have shoes or boards, or both. So, 16 students have neither.