Question

Nine is fifteen percent of what number?

Answer 1

We have:

Let x = unknown number

15% by x = 9 or

`(15)/(100)\cdot x=9`

And solve for x:

`\begin{gathered} 100\cdot(15)/(100)\cdot x=9\cdot100 \\ 15x=900 \\ (15x)/(15)=(900)/(15) \\ x=60 \end{gathered}`

Answer: the number is 60