Question

A bookstore sells used books at 40% discount off the regular price of the book when it was new. The price of a used book is 18$. What was the regular price of that book when it was new?

Answer 1

The regular price was $30.

Explanation:

The bookstore sells used books at 40% discount off the price of new books. This means, after the discount, the price of a used book will be 100% - 40% = 60% of the original price.

Now, if the price of the used book is $18, we know that is is 60% of the price of the book when it was new.

Let us call
`x`, the price of the book when it was new, then we know that

`0.6x=18` (this says that 60% of the original price is $18.)

We solve for
`x` and get

`x=(18)/(0.6) =30.`

The price of the book was $30 when it was new.