(8 5/27 - х) - 2 25/27 = 1 25/27
8 5/27 - х = 1 25/27 + 2 25/27
8 5/27 - х = 3 50/27 = 4 23/27
х = 8 5/27 - 4 23/27 = (8 - 4) + (5/27 - 23/27)=(8 - 3)+(32/27- 23/27) =3 9/27
х = 3 9/27 = 3 1/3
х = 3 1/3
40 1/2:2/3=81/2 X3/2=243/4=60.75
30 мин - 1/2, 15 мин - 1/4, 10 мин - 1/6, 6 мин - 1/10.