15-8 2/5*1 11/24+3 5/6

15 - 8 2/5 * 1 11/24 + 3 5/6 = 6 7/12

1) 8 2/5 * 1 11/24 = 42/5 * 35/24 = 49/4 = 12 1/4

2) 15 - 12 1/4 = 14 4/4 - 12 1/4 = 2 3/4

3) 2 3/4 + 3 5/6 = 2 9/12 + 3 10/12 = 5 19/12 = 6 7/12