Calculate the future value of $2000 in

a. Five years at an interest rate of 5% per year.

b. Ten years at an interest rate of 5% per year.

c. Five years at an interest rate of 10% per year.

d. Why is the amount of interest earned in part (a) less than half the amount of interest earned in part (b)?

Your brother has offered to give you either $5000 today or $10,000 in 10 years. If the interest rate is 7% per year, which option is preferable?