Question

if the price of a book is reduced by rupees 5, a person can buy 5 more books for rupees 300,find the original price of a book.

Answer 1

Here is the answer, I hope it is correct and you can understand

Answer 2

let the cost of each book be x
then no of books bought for 300= 300/x
if cp of each book= x-5
then no of books bought for 300= 300/x-5
a/q
300/x-5- 300/x=5
(300×x - 300(x-5))/(x-5)(x) =5
300x-300x+1500= 5x^2-25x
1500= 5x^2 -25x
5x^2-25x -1500=0
5( x^2 -5x-300)=0
x^2 -5x-300=0
x^2-20x+15x -300=0
x(x-20)+15(x-20)=0
(x+15)(x-20)=0
x=-15 or x=20
cp can never be negative
therefore original price of book is 20.