Environmental science problem...please help me!?

A herd of caribou on Edwardian Island was measured in 1959 to be 20 animals and the herd was growing at a steady rate of 10% annually. An expedition returned to Edwardian Island in 1994. Assuming the dynamics of the herd have not changed, how many caribou will there be? Show how you arrive with your answer.Environmental science problem...please help me!?It's a simple interest problem, assuming that the island is large enough to support a large herd.