Catholic High Sch 2006 PSLE Math Prelim Q36

There are 45 boys in a campsite. Out of these boys, 17 of them like cycling. 14 of them like swimming and 10 of them like both cycling and swimming. How many boys do not like cycling and swimming?

Solution


Like both ----- 10
Like cycling only ---- 17 – 10 = 7
Like swimming only ----- 14 – 10 = 4
(Total number of boys) like cycling, swimming or both -----
10 + 7 + 4 = 21

(Number of boys) do not like cycling and swimming -----
45 – 21 = 24

Answer: 24 boys do not like cycling or swimming.