Percent Increase formula: Using the percent increase formula, what is the percent increase from 20% to 30%?

Percent Increase formula: Using the percent increase formula, what is the percent increase from 20% to 30%?

• A. 50 percent
• B. 10 percent
• C. 200 percent
• D. 5 percent

Answer: (A)

Percent increase tells you how much a quantity grows relative to its original value. To go from 20% to 30%, the increase is 10 percentage points. But to express that as a percent increase, compare the change to the original amount: (30% − 20%) ÷ 20% × 100 = 10% ÷ 20% × 100 = 0.5 × 100 = 50%. So the increase is 50%. The other options come from mixing up percentage points with percent change or using the wrong base: a 10 percentage point change isn’t the same as a 10% increase; 200% would require the new value to be 60% (a 40-point rise, which is 200% of the original 20%); and 5% would come from dividing by 200 instead of by the original 20.

Percent increase tells you how much a quantity grows relative to its original value. To go from 20% to 30%, the increase is 10 percentage points. But to express that as a percent increase, compare the change to the original amount: (30% − 20%) ÷ 20% × 100 = 10% ÷ 20% × 100 = 0.5 × 100 = 50%. So the increase is 50%.

The other options come from mixing up percentage points with percent change or using the wrong base: a 10 percentage point change isn’t the same as a 10% increase; 200% would require the new value to be 60% (a 40-point rise, which is 200% of the original 20%); and 5% would come from dividing by 200 instead of by the original 20.