1. Find the present value of an annuity which pays $500 at the end of each half-year for 240 months if the rate of interest is 9% compounded quarterly.
2. Find the accumulated value of a 10 year annuity-due of $100 per year if the effective annual interest rate is 5%.
3. A monthly annuity starts on 1 February 1998 and ends on 1 January 2001 (inclusive). If the value of this annuity on 1 January 2001 is $8000 and interest is 11% p.a. compounded monthly, what is its value on 1 January 1998?