1) 7 1/2 * 2 2/3 = 15/2 * 8/3 = 20
2) 12 1/4 : 7/2 = 49/4 * 2/7 = 7/2=3,5
3) 20 - 3,5=16,5
4) 110 * 3/5 = 66
5)16,5:66=0,25=1/4
6) 3 3/8 + 2 3/4 = 3 3/8 + 2 6/8 = 5 9/8 =6 1/8
7) 24 : 2 2/5 =24:2,4=10
8)6 1/8:10 = 49/8 * 1/10 = 49/80
9) 1/4 + 49/80 = 20/80 + 49/80 = 69/80
ответ: 69/80