Use proportions to figure out the amount of children in the club.
If 40 is 25%, use the following formula to find the total amount:
[tex] \frac{40}{25} = \frac{x}{100} [/tex]
Use cross multiplication.
40 * 100 = 4000
25 * x = 25x
25x = 4000
Divide both sides by 25.
x = 160
There are 160 total children in the club.