1 2/3 * 30 = 5/3 * 30/1 = 150/3 = 50
12 * 3/2 =36/2 =18
15/4 * 16/3 = 240/12 = 20
15/7 * 14/3 = 210/21 = 10
10/3 : 5/18 = 10/3 *18/5 = 180/15 = 12
21/2 : 3/2 = 21/2 * 2/3 = 21/3 =7
11/3 : 1/8 = 11/3 *8/1 = 88/3 = 29 1/3
1.3/5:7/8=18/5:7/8=18/5*8/7=144/35=4 4/5
2.2 6/7:5/9=20/7:5/9=20/7*9/5=180/35=5 5/35=5 1/7
3.3 1/5:1/5=16/5:1/5=16/5*5=16
0.2=2/10=1/5