Question

18 is 72% of what number?

Answer 1

18 is 72% of 25

Explanation:

"Percent" or "%" means "out of 100" or "per 100", Therefore 72% can be written as `72/100`.

When dealing with percents the word "of" means "times" or "to multiply".

Finally, lets call the number we are looking for "n".

Putting this altogether we can write this equation and solve for `n` while keeping the equation balanced:

`18 = 72/100 xx n`

`color(red)(100)/color(blue)(72) xx 18 = color(red)(100)/color(blue)(72) xx 72/100 xx n`

`1800/color(blue)(72) = cancel(color(red)(100))/cancel(color(blue)(72)) xx color(blue)(cancel(color(black)(72)))/color(red)(cancel(color(black)(100))) xx n`

`25 = n`