Question

If 9% of a number is 18, what is the number?

Answer 1

The number is `200`

Explanation:

Let the number be `x`

`9` percent of the number means
`color(white)("XXX")9/100 xx x`

So if `18` is `9` percent of the number:
`color(white)("XXXXXXXXXX")18=color(white)("XXXX")9/100 xx x`

`color(white)("XXX")rarr 100/9 xx 18 = 100/9 xx 9/100 xx x`

`color(white)("XXX")rarr 100/cancel(9) xx cancel(18)^2 = cancel(100)/cancel(9) xx cancel(9)/cancel(100) xx x`

`color(white)("XXX")rarrcolor(white)("XXXXX")200 = color(white)("XXXXXXXXX")x`