1) 1 3/5 * 8 = 8/5 * 8 = 64/5
2) 29/10 * 5 = 29/2
3) 64/5 +29/2 = 128/10 + 145/10 = 273/10
4) 75/10 * 1/3 = 25/10
5) 25/10 - 5/10 = 20/10 = 2
6) 273/10 : 2 = 273/10 * 1/2 = 273/20
7) 60 - 18 3/4 = 240/4 - 75/4 = 165/4
8) 165/4 : 25 = 165/4 * 1/25 = 33/4 * 1/5 = 33/20
9) 7/12 +0,15 = 7/12 +15/100 = 700/1200 + 180/1200 = 880/1200 = 88/120 = 44/60 = 22/30 = 11/15
10) 11/15 * 15 = 11
11) 33/20 : 11 = 33/20 * 1/11 = 3/20
12) 273/20 + 3/20 = 276 / 20 = 138 /10 = 13,8