Question

A discount of 16% on the marked price of a book enable a men to buy a pen that cost rate 80 how much did he pay for the book

Answer 1

let the price of the book be Rs.100.  Then the price of the pen would be Rs.16.

So when price of pen is 16, price of book is 100

when price of pen is 1, price of book is 100/16

when price of pen is 80, price of book is 100/16x80 = 500

now he got a discount of Rs.80.  So he paid 500 - 80 = Rs.420 for the book.