A bookseller bought a certain number of books for 337.50 and sold some of them at the cost price 213.75. Find the least number of books left with him.

A bookseller bought a certain number of books for 337.50 and sold some of them at the cost price 213.75. Find the least number of books left with him.

A bookseller bought a certain number of books for 337.50 and sold some of them at the cost price 213.75. Find the least number of books left with him.

A bookseller bought a certain number of books for 337.50 and sold some of them at the cost price 213.75. Find the least number of books left with him.
The first step in this problem is determining the cost per book. To do this you must find the greatest common factor of each of the two numbers given.The factors of 337.50 = 5 x 5 x .05 x 9 x 30The factors of 213.75 = 5 x 5 x .05 x 9 x 19When you multiply the common factors you get  11.25 which equals the cost of the book. At this cost the bookseller bought 30 books and sold 19, leaving a balance of 111 books.I hope that this helps you understand the problem more clearly.