Question

If the price of a book is first decreased by $25\%$ and then increased by $20\%$, the net change in the price of the book is

• A. $10\%$ decrease
• B. $5\%$ decrease
• C. No change
• D. $5\%$ increase

Answer 1

The correct option is A $10\%$ decrease

Let the original price of the book be Rs. $100$.

Decreased price of the book $=$ Rs. $75$

Increased price of the book after $20\%$ increase
$=\frac{120}{100}\times$ Rs. $75=$ Rs. $90$
$\therefore$ Net change in price $=$ Rs. $10$ decrease

$\therefore$ $\%$ change $=\frac{10}{100}\times 100=10\%$ decrease