Future Value of Multiple Annuities Assume that you contribute $110 per month to a retirement plan for 20 years. Then you are able to increase the contribution to $210 per month for another 20 years. Given a 6.5 percent interest rate, what is the value of your retirement plan after 40 years? $125,476 $124,800 $300,240 $251,198 Solution The future value of the initial investment of $ 110 per month for 20 years, based on the Future Value formula will be $ 51,249. The future value of the next contribution of $ 210 per month for another 20 years, based on the Future Value formula will be $ 97,840. Thus, the total of both the future values taken together is $ 149,089. Since $ 125,476 is closest to this value, we can assume that to be the value of the retirement plan after 40 years..