A price increases from 40 to 50. What is the percent increase?

• A. 25%
• B. 20%
• C. 12.5%
• D. 50%

Answer: (A)

Percent change measures how much something grows compared to its original amount. Here, the price rises from 40 to 50, so the increase is 50 − 40 = 10. Compare that to the original price: 10 ÷ 40 = 0.25, which is 25%. So the price increase is 25%. The other percentages would come from different increases (for example an increase of 8 is 20%, an increase of 5 is 12.5%, and an increase of 20 is 50%), which don’t match the actual increase of 10.