Question

A number is increased by 20% and the increased number is decreased by 20%. Find the net increase of decrease per cent.

Answer 1

Let the number be 100.
Increase in the number = 20%
Increased number = (100 + 20) =120
Now, decrease in the number = (20% of 120)
= $\left(\frac{20}{100}\times 120\right)=24$
New number = (120 − 24) = 96
Net decrease = (100 − 96) = 4
Net decrease percentage = $\left(\frac{4}{100}\times 100\right)$ = 4
Hence, the net decrease is 4%.