а) 1/2 * 4/5 * 5/6 = 1/1 * 2/5 * 5/6 = 2/5 * 5/6 = 1/3 * 1/1 = 1/3
б) 7/8 * 4/35 * 9/10 = 1/2 * 1/5 * 9/10 = 1/10 * 9/10 = 9/10 = 0,9
в) 42/85 * 17/21 * 35/36 = 2/5 * 1/1 * 35/36 = 2/5 * 35/36 = 1/1 * 7/18=7/18
г)14/19 * 95/96 * 16/35 = 7/1 * 5/48 = 35/48