a) The amount of change is .20 (20 cents) so we need to find what percent of $4.00 is .20...
4 * x = .20
x = .20/4 = .05
Multiply by 100 (move decimal 2 places to the right) to change decimal to percent.
.05 = 5% increase
b)The increase is .75. What percent of 3.00 is .75
3 * x = .75
x = .75/3
x = .25 x 100 = 25% increase
c) The amount of change is .75 but this time we are going from 3.75 to 3.00 so we find out what percent .75 is of 3.75.
3.75 * x = .75
x = .75/3.75
x = .20 x 100 = 20% decrease