A number is increased by 30% and then decreased by 30%. Finally, the number:

Correct option is D

Given:

Number is first increased by 30%

Number is then decreased by 30%

Solution:

Let the number be 100

Then after 30% increase number will be 100 + 30% of 100 = 130

Number after 30% decrease = 130 - 30% of 130

= 130 - 39 = 91

Number is decreased by 100 - 91 = 9%

Alternative Method:

Successive Percent = $$x + y - \frac{(x)(y)}{100}$$​​

Successive Percent = $$30-30+ \frac{(-30)(30)}{100}$$​​

= 0 - 9 = -9%

(-) sign indicates there’s an decrease