At age ​18, someone sets up an IRA​ (individual retirement​ account) with an APR of ​4%. At the end of each month he deposits ​$40 in the account. How much will the IRA contain when he retires at age​ 65? Compare that amount to the total deposits made over the time period.

just plug your numbers into the future value formula for annuities.

deposits made are (65-18)*12*40

To calculate the future value of the IRA account, we can use the formula for compound interest:

FV = P * (1 + r/n)^(n*t)

Where:
FV = future value
P = principal amount (initial deposit)
r = annual interest rate (expressed as a decimal)
n = number of times the interest is compounded per year
t = number of years

In this case, the principal amount is $40, the annual interest rate is 4% (or 0.04 as a decimal), and the interest is compounded annually. The time period is 65 - 18 = 47 years.

FV = $40 * (1 + 0.04/12)^(12*47)
FV = $40 * (1.003333)^564
FV = $40 * 360.40407074
FV ≈ $14,416.16

So the IRA will contain approximately $14,416.16 when he retires at age 65.

To determine the total deposits made over the time period, we can multiply the monthly deposit amount by the number of months:

Total deposits = $40 * 12 * 47
Total deposits = $22,560

Therefore, the IRA will contain more money ($14,416.16) than the total deposits made ($22,560) over the time period.