Question

50% of children in a sports club go swimming. 50%of the children who go swimming also dive. Five children swim and dive. How many children are in the sports club?

Answer 1

There are 20 children in the club.

Explanation:

Let X = the total number of children in the sports club.

50% of x (which can be written as 0.50x) swim.

50% of that ^^^ number also dive. This could be written as 0.5x * 0.5 = 0.25x.

We are told that 5 children swim & dive.

So: 0.25x= 5.

Solve for x.

0.25x= 5

0.25x/0.25 = 5/0.25

x = 20

There are 20 children in the club.

Let's check the answer:

20 children

50% swim = 10 children who swim.

50% of the swimmers also dive = 5 children who swim & dive, which is exactly what the problem says so our answer is correct.