The graph below shows the distance a train traveled over time. According to the graph, at what speed did the train travel?
A.18 Miles per hour
B.30 Miles per hour
C.50Miles Per hour
D.72 Miles per hour

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.