11/20 / (5/12 - 7/8) + 3 * 1 7/15

1) 5/12 - 7/8 = 5 * 2/12 * 2 - 7 * 3/8 * 3 = 10/24 - 21/24 = -11/24. 2) 11/20 : (-11/24) = 11/20 * (-24/11) = -24/20 = -6/5. 3) 3 * 1 7/15 = 3 * 22/15 = 66/15 = 22/5. 4) -6/5 + 22/5 = 16/5 = 3 1/5.