Answer:
9%
Explanation:
Let the required number be 100.
Now, according to the question, the number is first increased by 30 %
⇒ 100 + 30 % of 100
⇒ 100 + [(30*100)/100]
⇒ 100 + 30
⇒ 130
Then, it is decreased by 30 %
⇒ 130 - (30 % of 130)
⇒ 130 - [(30*130)/100]
⇒ 130 - 39
⇒ 91
Net Decrease = 100 - 91
= 9
Percent Decrease = (Change in number*100)/100
⇒ (9*100)/100
= 9 %