Question

SHOW THE EQUATION YOU SET UP10% of what number is 90?

Answer 1

Recall that the x% of y can be computed using the following expression:

$y\cdot\frac{x}{100}\text{.}$

Now, let n be the number such that its 10% is 90, then we can set the following equation:

$90=n\cdot\frac{10}{100}\text{.}$

Simplifying the above equation we get:

$90=\frac{1}{10}n\text{.}$

Multiplying the above equation by 10 we get:

$\begin{gathered} 90\times10=\frac{1}{10}n\times10, \\ n=900. \end{gathered}$

Answer:

Equation:

$\frac{1}{10}n=90.$

Number: 900.