What is the definition of a ratio

Can someone me do math because i am having a breakdown rn because i don’t get it

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.

If you have 12 feet of string and you cut it into equal length of 5 inches each how much string will be left