Alex wishes to deposit $2,500 at the end of each month to his savings account which has an annual interest rate of 4.8% convertible monthly. How many months it will take Alex to accumulate $20,000 and what will be the amount of his final deposit? Given the annual nominal rate of interest of 5% compounded monthly, calculate the present value of an annuity which pays $3,000 at the end of each six months for four years