(7/8 - 3/5) : (2/3 + 1/2) * (60 : 4 5/7) = 3
1) 7/8 - 3/5 = (35-24)/40 = 11/40
2) 2/3 + 1/2 = (4+3)/6 = 7/6
3) 60 : 4 5/7 = 60/1 : 33/7 = 60/1 * 7/33 = 20/1 * 7/11 = 140/11
4) 11/40 : 7/6 = 11/40 * 6/7 = 11/20 * 3/7 = 33/140
5) 33/140 * 140/11 = 3/1 * 1/1 = 3