# Please I need help for the number one question in my mathematics ?

Apr 5, 2018

63 books where each one is 4 cm wide

#### Explanation:

Each book is 3cm wide. There is a count of 84 books so the shelf length is $84 \times 3 \text{cm" = 252} c m$

We change the books to ones that are 4cm thick.

The count of these books is $\left(252 \cancel{\text{cm"))/(4cancel("cm}}\right) = 63 \frac{1}{2}$

Did you know you can cancel out units of measurment the same way you can numbers?

You can not but $\frac{1}{2}$ a book on so we have 63 books