What is the minimum number of years a person must deposit 40

What is the minimum number of years a person must deposit $400 per year in order to have at least $10,000 on the date of the last deposit? Use an interest rate of 8% and round off to the higher integer year.

Solution

The formula used to calculate

Maturity amount = Yearly deposit*((1+interest rate)^n - 1)/interest rate)

10000= 400*((1+0.08)^n - 1)/0.08)

10000/400 =  ((1+0.08)^n - 1)/0.08)

25*0.08 = ((1+0.08)^n - 1)

3 = (1.08)^n

Solving for n, we get n = 14.3 or 14 years