Question

A number is increased by 40 % and then decreased by 40 %. Find the net increase or decrease percent.

• A. $16$%
• B. $4$%
• C. $10$%
• D. $5$%

Answer 1

The correct option is A $16$%

Let the number be $100$.

Increase in the number$=40\%=40\%$ of $100$

$=\frac{40}{100}\times 100=40$

$\therefore$ increased number $=100+40=140$

This number is decreased by $40\%$

$\therefore$ decrease in number $=40\%$ of $140$

$=\frac{40}{100}\times 140$

$=\frac{5600}{100}=56$

$\therefore$ new number $=140-56=84$

Thus, net decreases $=100-84=16$

Hence, net percentage decrease $=\frac{16}{100}\times 100\%$

$=\frac{1600}{100}\%=16\%$