1) 3 3/4 = 15/4
2) 15/4 - 6/10 = 15/4 - 3/5 = (75 - 12)/20 = 63/20
3) 63/20 : 3/10 = 63/20 * 10/3 = 21/2
4) 1 5/7 = 12/7
5) 17/24 + 12/7 * 21/2 = 17/24 + 6 * 3 = 17/24 + 18 = 17/24 + 432/24 = 449/24