finance
posted by Qoo .
You have an investment opportunity which yields 9% per year. About how many years will it take your initial investment of $10,000 to grow to a total of of $40,000? Please give your answer as a whole number

Pt = 10000 + 10000*0.09*t = 40000.
900t = 4000010000 = 30000.
t = 30000 / 900 = 33.33 Years or 33yrs. 
Use financial calculator to solve for the interest rate involved in the following future value of an annuity due problem. The future value is $57,000, the annual payment is $7,500, and the time period is six years