Mr Trump is 40 years old and will retire at age 65. He will receive retirement benefits but the benefits are not going to be enough to make a comfortable retirement life for him. Trump has estimated that an additional $20,000 a year over his retirement benefits will allow him to have a satisfactory life. How much should Trump deposit today in an account paying 6 percent interest to meet his goal?

Assume Trump will have 15 years of retirement.