Question

a boy reads 4/5 of a book and finds that there are still 60 pages left to read.find the number of pages in the book.

Answer 1

A boy reads 4/5 of a book 
pages left= 1 - 4/5 =1/5
Let the total no of pages = x
therefore
1/5 * x =60 
x =300
the number of pages in the book = x=300

Answer 2

The total number of pages in the book is 300.

Solution:

Let us assume that the total number of pages in the book is x

The boy reads $\frac{4}{5}$ of a book

So he read total $\frac{4x}{5} pages$

Hence the pages of the book remaining is $\left(x-\frac{4 x}{5}\right)=\frac{x}{5}$

It is given total 60 pages remaining of the book.

Hence we can say,

$\frac{x}{5}= 60$

$x = (60\times5) = 300$

The total pages in the book =300