**Question **# A monopolist who employs m workers finds that they produce q = 2m(2m +1)² units of product per day. \text { The total revenue } r \text { (in rands) is given by } r=\frac{50 q}{\sqrt{1000+3 q}} \text {. Determine the marginal } revenue when there are 12 workers. A debt of R5000 due five years from now and R5000 due ten years from now is to be repaid by a payment of R2000 in two years, a payment of R4000 in four years, and a final payment at the end of six years. If the interest rate is 2.5% compounded annually, how much is the final payment.