It took Jackie two hours to mow the lawn period two weeks later, it took her 1 1/2 hours to mow the lawn. What can be said about the amount of power used by Jackie the second time she mowed the lawn.

Answer: We could say that Jackie's time decreased by 25%.

The first time she mowed the lawn it took her 2 hours. The second time she mowed the lawn it took her 1.5 hours. That is a difference of 0.5 hours.

If we write a fraction of the difference over the original amount, we get 0.5/2. This can be simplified to 25%.

Her time decreased by 25%.