Please assist with the following problem
Find the present value of a 3-year, R20,000 ordinary annuity deposited into an account that pays 12% interest compounded monthly. Calculate the present value of the annuity in the following ways:
i. As three single cash flows discounted at the stated rate of interest
ii. As three single cash flows discounted at the effective rate of interest.
iii. As 3 year annuity discounted at the effective rate of interest.