Question

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

Answer 1

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 `84xx3"cm" = 252"cm`

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

The count of these books is `(252cancel("cm"))/(4cancel("cm"))=63 1/2`

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

You can not but `1/2` a book on so we have 63 books