Another financial algebra question please look into it!

Isee the amount was $90.00 then reduced to $75.00 , what is the percent ?

It takes a total of 6 hours to fill up an inground backyard pool using a standard house. a function can represent this situation to represent the amount of water in the pool until it is full a function of time the hose is running. determine the domain for the function

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.