The equation for percent increase from A to B is:

The equation for percent increase from A to B is:

• A. ((B−A)/A) × 100%
• B. ((A−B)/B) × 100%
• C. (B−A) × 100
• D. (A/B) × 100

Answer: (A)

Percent increase from A to B measures how much A has grown relative to its original size. The amount of increase is B minus A, and to turn that into a percentage you compare the increase to the original value A. So you take (B−A), divide by A to get the proportion of the original amount that was gained, and multiply by 100% to express it as a percent. That gives the formula ((B−A)/A) × 100%. For example, if A is 50 and B is 60, the increase is 10. The percent increase is (10/50) × 100% = 20%. The other forms don’t fit this idea: using (A−B)/B would measure a change from B back to A and yields a negative result when B is larger than A; (B−A) × 100 would give a scaled change but not a percent; (A/B) × 100 would express what percent B is of A, not the percent increase from A to B.

Percent increase from A to B measures how much A has grown relative to its original size. The amount of increase is B minus A, and to turn that into a percentage you compare the increase to the original value A. So you take (B−A), divide by A to get the proportion of the original amount that was gained, and multiply by 100% to express it as a percent. That gives the formula ((B−A)/A) × 100%.

For example, if A is 50 and B is 60, the increase is 10. The percent increase is (10/50) × 100% = 20%.

The other forms don’t fit this idea: using (A−B)/B would measure a change from B back to A and yields a negative result when B is larger than A; (B−A) × 100 would give a scaled change but not a percent; (A/B) × 100 would express what percent B is of A, not the percent increase from A to B.