Question

A shopkeeper buys a number of books for RS.80. If he had bought 4 more books for the same amount,each book would have cost rs.1 less. How many books did he buy?​

Answer 1

Answer:

VarghesebijupbaxnsHelping Hand

Eq no 1:- total books purchased = x

Therefore unit price = 80/ x

Eq no 2:- 4 extra book purchased on same price = ×+4 =80

Therefore unit price = 80/(×+4)

Difference of price is Rs. 1

Hence 80/× - 80/(x-4) =1

By solving the equation

320/ (xpower2 + 4x)=0

Xpower2+4x-320=0

X(X+20) -16(X+20)=0

(X+20) (X-16)=0

X=-20, X=16

We negate negative answer

Therefore no of books brought =16