Question

A reduction of 10% in the price of Apples enables a person to buy 400 gram weight more apples for Rs 180 find the original price per kg weight

Answer 1

Define x:

Let the price of the apple be Rs x per gram

Price after reduction = Rs0.9x per gram

 

Before reduction:  

Weight of apples bought = 180/x

After reduction:

Weight of apples bought = 180/0.9x

Solve x:

The difference is 400g

⇒ 180/0.9x – 180/x =  400

180/0.9x – 180/x =  400

Cross multiply:

180x - 180 (0.9x) = 400 (0.9x)(x)

Evaluate brackets:

180x – 162x = 360x²

18x = 360x²

360x² – 18x = 0

Take out common factor 18x:

18x(20x – 1) = 0

Apply zero product property:

20x - 1 = 0 or 18x = 0

x = 1/20 or x = 0 (rejected, since price cannot be zero)

x = 0.05

Find the original price per kg:

Price per gram = x = 0.05

Price per kg = 0.05 x 1000 = Rs 50

Answer: The original price is Rs 50 per kg.