Rebecca gave the cashier $20 to pay for 3 tickets to a museum. The cashier gave her back $1.28 back in change. Each ticket cost the same amount. How much did each ticket cost?

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.