Explanation
Given:
Increment in number = 20% of the number
Decrement in number = 20% of the new number
Concept used:
Net increase or decrease percent = {(Original number or Final number) - (Final number or original number) ÷ Original number} × 100
Calculation:
Let the original number be 100
When the number is increased by 20%
New Number = 100 + 20% of 100
⇒ 100 + 20
⇒ 120
Now, the number is decreased by 20%
Final number = New number – 20% of new number
⇒ 120 – 20% of 120
⇒ 120 – 24
⇒ 96
∴ Net Decrease in percentage = { (100 – 96) / 100} × 100
⇒ {4/100} × 100
⇒ 4%
∴ The net decrease percentage is 4%