Final answer:
To find the amount that could be withdrawn at t = 10, calculate the future value of the 10 deposits using the formula for the future value of an annuity.
Step-by-step explanation:
To solve this problem, we can use the formula for the future value of an annuity: FV = P * [(1 + r)^n - 1] / r, where FV is the future value, P is the periodic deposit, r is the interest rate per compounding period, and n is the number of compounding periods.
a) To find the amount that could be withdrawn at t = 10, we need to calculate the future value of the 10 deposits. The first deposit is $5,000, and it decreases by $300 each year. The interest rate is 12%. Substituting these values into the formula, we have:
FV = 5000 * [(1 + 0.12)^10 - 1] / 0.12