Percentage increase/decrease = (Change in value)/(Original value) × 100%

Note:Original value is in denominator

#### Suppose I have 100 rupees. And Harshit gave me Rs 20. What is the percentage increase in money I have?

Original amount = Rs 100

Amount after increase = Rs (100 + 20)

= Rs 120

Change in value = 120 − 100

= 20

Thus,

Percentage increase = (Change in value)/(Original amount) × 100%

= 20/100 × 100%

= 20%

Suppose I have 100 rupees. And, Harshit took Rs 25 from me. What is the percentage decrease?

Original amount = Rs 100

Amount after decrease = Rs 100 − 25

= Rs 75

Change in value = 100 − 75

= 25

Thus,

Percentage decreased = (Change in value)/(Original amount) × 100%

= 25/100 × 100%

= 25%