The combined one day work of Pooja and Ritu is 1 divided by (120 divided by 7), which equals 7 divided by 120. Let Ritu's one day work be x; then Pooja's one day work is (3 divided by 4)x. The sum of their one day works is x plus (3 divided by 4)x equals 7 divided by 120, so (7 divided by 4)x equals 7 divided by 120, yielding x equals 1 divided by 30. Ritu alone takes 30 days, and Pooja takes 1 divided by ((3 divided by 4) times (1 divided by 30)), which equals 40 days. Therefore, Pooja finishes it in 40 days and Ritu in 30 days.