A value changes from 80 to 100. What is the percent change?

A value changes from 80 to 100. What is the percent change?

• A. 12.5%
• B. 20%
• C. 25%
• D. 50%

Answer: (C)

Percent change shows how big the change is relative to the starting value. Use (new − original) ÷ original × 100. Here the original value is 80 and the new value is 100, so the change is 20. Since 20 is 25% of 80, the percent change is 25%. Intuitively, you’re increasing the starting amount by a quarter to reach 100. The other options would correspond to different increases (for example, a 12.5% increase would be 10, a 20% increase would be 16, and a 50% increase would be 40).

Percent change shows how big the change is relative to the starting value. Use (new − original) ÷ original × 100. Here the original value is 80 and the new value is 100, so the change is 20. Since 20 is 25% of 80, the percent change is 25%. Intuitively, you’re increasing the starting amount by a quarter to reach 100. The other options would correspond to different increases (for example, a 12.5% increase would be 10, a 20% increase would be 16, and a 50% increase would be 40).