2. A stack of 500 sheets of paper is 2.5 inches high. Each sheet of paper is 8.5 inches wide and 11 inches long. A person places more sheets onto the stack, making the total volume of the stack 561 cubic inches. Approximately how many more sheets of paper were added to the original stack of paper?
1) 200
2) 700
3) 1,200
4) 1,700