Question

15 books to 21 books the percentage change is

Answer 1

Given:

Original number of books = 15 books

New number of books = 21 books

Let's find the percentage change.

To find the percentage change, apply the formula below:

`\text{Percentage change = }\frac{New\text{ value - Original value}}{Original\text{ value}}\ast(100)/(1)`

Input values into the formula.

We have:

`\begin{gathered} \text{Percentage change = }(21-15)/(15)\ast(100)/(1) \\ \\ \text{Percentage change = }(6)/(15)\ast(100)/(1) \\ \\ \text{Percentage change = }0.4\ast100=40\text{ \%} \end{gathered}`

Therefore, the percentage change is 40 percent.

ANSWER:

40%