basically there are 58 boys and each one can only answer once. Its mentioned that 20 boys dont play baseball or basketball so you'll write that down. Then its mentioned that 31 dont play baseball so you subtract 20 from 31 since each boy only answer once. your all left with 11 boys who dont play baseball but play football. In total 31 boys dont play baseball at all. 16 of them play football but earlier we figured out that 11 of those 16 boys also play foot ball dont play baseball so you subtract 11 from 16 and you left with 5 boys who play baseball and football together. The total number of football players is 16. your going to want to subtract 31 from 58 to get the remaining boys who play baseball which will be 27. Finally you subtract 5 from 27 and you'll get 22 boys who dont play football but play baseball. Hoped this helped if not then just look at the picture.
