Two classmates, Mary and Jenny, plan to meet in the computer lab to type up their research papers. Mary can type at a speed of 2 pages per hour, whereas Jenny can type 1 page per hour. So far, Mary already has 8 pages typed up, compared to Jenny's 13 pages. Once they sit down and start typing together, the two students will reach the same page count before too long. How long will that take? What will the page count be?