Question

The price of a refrigerator is increased by 25%.
By what percent should the price of the refrigerator
be decreased to bring it back to the original price?​

Answer 1

Given:

• The price of a refrigerator is increased by 25%

To find:

• what percent should the price of the refrigerator be decreased to bring it back to the original price?

Solution:

• Let the initial price be 4x. When it is increased by 25%

• 5x should be decreased by 'y%' to make it 4x again.

According to the question

increase in the percentage :

$4x + ( \frac{25}{100} ) \times 4 = 5x$

Decreased in the percentage :

$5x - ( \frac{y}{100}) \times 5x = 4x$

$5x - 4x = ( \frac{y}{100} ) \times 5x$

$x = ( \frac{y}{100}) \times 5x$

$y = 20$

Hence 20% is correct answer.

Answer 2

Answer:

Required percentage is 20%.

Step-by-step explanation:

Let price of the refrigerator is x rupees.

But now price of the refrigerator is increased by 25%.

So now price of refrigerator is $x \times \frac{100 + 25}{100} = x \times \frac{125}{100} = x \times \frac{5}{4} = \frac{5x}{4}$rupees.

Let y% of price of refrigerator be decreased.

According to question,

$\frac{5x}{4} \times \frac{100 - y}{100} = x$

$\frac{100 - y}{100} = x \times \frac{4}{5x}$

$\frac{100 - y}{100} = \frac{4}{5}$

By cross multiplication,

$5 \times (100 - y) = 4 \times 100$

$500 - 5y = 400$

$5y = 500 - 400 = 100$

$y = \frac{100}{5} = 20$

Required percentage is 20%.