Question

A reduction of 20% in the price of flour enables akriti to buy an extra 5 kg of it for ₹320 . Find the original price per kg and the reduced price per kg.

Answer 1

Let price of flour is Rs. X/kg .
.
after price reduction
$x \times \frac{80}{100} \\ = \frac{4x}{5}$
ATQ
$\frac{320}{ \frac{4x}{5}} - \frac{320}{x} = 5 \\ \frac{1600}{4x} - \frac{320}{x }= 5 \\ \frac{1600 - 1280}{4x} = 5 \\ \frac{320}{4x} = 5 \\ x = 16$
original price =Rs.16/kg
Reduced price=Rs. 12.8/kg

Answer 2

Solution:

Reduction is 20%

320×20/100

32×2=64

5kg =64

1kg = 64/5

=12.8 is reduced price (b)

As reduction is 20%

80% = 12.8

100%=128/800×100

128/8=16 is original price (a)