27/8 : 2 - 13/16 - 3/10 * (4-2 7/12).

27/8 : 2 - 13/16 - 3/10 * (4 - 31/12) = 27/16 - 13/16 - 3/10 * (48/12 - 31/12) = 14/16 - 3/10 * (17/12) = 7/8 - 51/120 = 7/8 - 17/40 = (35 - 17) / 40 = 18/40 = 9/20.