Question

out of 40 people,17 have brothers,22 have sisters and 9 have both.how many people have neither brothers nor sisters

Answer 1

17 - 9 = 8 have only brothers
22 - 9 = 13 have only sisters
9 have both brothers and sisters
40 - 8 - 13 - 9 = 10 have neither.

Answer 2

noice