Question

Hydra are small freshwater animals. They can double in number every two days in a laboratory tank. Suppose one tank has an initial population of 60 hydra. When will there be more than 5000 hydra? How can a table help you identify a pattern? What function models the situation (remember that in the function 7=a*b(to the power of x)? I believe the answer is "after 7 2-day periods", but I do not know how to set it up.