Suppose he bought b books, then he paid 80/b Rupees per book.Originally Posted byanjana

If he had bought b+4 books for 80 Rupees he would have paid 80/(b+4)

Rupees for each book, but we are told this is 1 Rupee less than he did

pay per book so:

80/(b+4)=80/b - 1

This is the equation you need to solve to find b the number of books he

bought.

RonL