Actually that is the formula for interest compounded n times a year. For "compounded monthly", n= 12.

Just evaluate the formula:if 15,000 is invested originally what is the value of the investment after 5 years

So A= 3P. Solve for t. An obvious first step is to cancel the "P"s. Then take a logarithm of both sides.how long will it take for an investment to triple in value