Paul borrows $4000 at 18% simple interest. He is to repay the loan by paying $1000 at the end of 3 months and making two equal payments at the end of 6 months and 9 months. Find the size of the equal payments, using as the focal date (a) the end of 6 months, (b) the present. Ans. (a) $1693.97; (b) $1692.01