✔ 最佳答案
(a) -15000 + 20000/(1 + 5%)^3 = 2276.75197
(b) Let the internal rate of return is x
-15000 + 20000/(1 + x)^3 = 0
x = 10%
If the interest rate is 12%, this means that the return of investment is less than put the money into the bank. So, I would not conduct the investment.