2 3/4 + 1 2/3;
3+9/12+8/12=3+17/12=4 5/12;
8 3/5 + 1 2/3;
9+ 9/15+10/15=9+19/15=10 4/15;
7/20 + 8 3/4;
8+7/20+15/20=8+32/20=9 12/20= 9,6;
12 5/6 + 4/15;
12+25/30+8/30=12+33/30=12,1;
8 5/6 + 2 3/8;
10+20/24+9/24 =10 +29/24=11 5/24;
1 4/5 + 3 11/30
4+ 24/30+11/30=4+35/30=5+1/6=5 1/6.