If 80000 is invested at 8 compounded quarterly how long will

If $80,000 is invested at 8% compounded quarterly, how long will it take for the investment to triple in value?

Solution

Amount = Principal( 1 + rate/ no. of times compounding) ^(years*no. of compounding)

  investment to triple in value : 3P = P ( 1+ 0.08/4)^4t

where t is no. of years.

3 = ( 1.02)^4t

take log on both sides:

ln3 = 4t*ln(1.02)

t = 13.87 years