A laser beam with an output of 6 milliwatts is directed into a series of mirrors. The laser beam loses 5% of its power every time it reflects off of a mirror. The power p(n) is a function of the number n of reflections.

This is a very similar question that will help you:

https://web2.0calc.com/questions/help-exponential-functions

Cal,

You are doing a really good job of finding things.

I should hire you as my own personal research officer. LOL

Hehe... Thanks