The monthly interest rate on Bill’s credit card is 2% (24% nominal annual rate convertible monthly). For each of 9 consecutive school months, he borrows 500 at the beginning of the month. At the end of each of these 9 months, he makes the minimum payment of 25. Then, during the 3 remaining months of the year, he pays back X at the end of each month and borrows nothing. At the end of the 12 months his balance is 0. Determine X.