The cost of a gallon if gas recently doubled. By what percent did it increase?

If a price doubles, then it increases by 100%

Step-by-step explanation:

To find the percent increase, use the percent increase formula below.

(New - Old) / Old * 100 = percent increase

You can choose any number to be the old number and you'll get the same answer. For this purpose, we'll use 65. This would make the new value 130.

(130 - 65) / 65 * 100 = Percent Increase

65/65 * 100 = Percent Increase

100% = Percent Increase