1) 3 2/5 : 17/20 = 17/5 : 17/20 = 20/5 = 4 2) 4 1/2 - 4 = 1/2 3) 11/15 * 1/2 = 11/30 4) 11/30 + 1 11/20 = 22/60 + 1 33/60 = 1 55/60 = 1 11/12 Ответ 1 целая 11/12