If Lynne bought a bag of grapefruit, 1 and 5\8 pounds of apples, and 2 and 3\16 pounds of bananas. the total weigh was 7 and 1\2 pounds. how much did the bag of grapefruit weigh?

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.