If a number is increased by 20% and then it is decreased by 10%. Its net increase or decrease is:

Correct option is A

Given:
A number is increased by 20% and then decreased by 10%.
Formula Used:
Net effect = (a + b + (a * b) / 100), where 'a' is the percentage increase and 'b' is the percentage decrease.
Solution:
Here, a = 20 and b = -10.
So, Net effect = 20 + (-10) + (20 * (-10)) / 100.
Net effect = 20 - 10 - 2 = 8.
Thus, the net increase is 8%.
Alternate Method

Let the original number be 100.
New value after a 20% increase = 100 + 20% of 100= 120
Value after a 10% decrease on 120 = 120 – 10% of 120 = 108
Net change = Final value - Initial value
Net change = 108 - 100 = 8
Percentage Increase = $$\frac{8}{100} \times 100$$​ = 8%
- Therefore, the net increase in the value is 8%.