Some investors want to know the "doubling time" of an investment—that is, the amount of time it will take for the investment to grow to twice its initial value. Suppose the value of an investment in...

Some investors want to know the "doubling time" of an investment—that is, the amount of time it will take for the investment to grow to twice its initial value. Suppose the value of an investment in an account earning an annual interest rate of 12% compounded daily grows according to the equation

 where

 is the initial value of the investment andt is the time in years. Find the doubling time for the investment. Round to the nearest year.

t =  yr