12/3 * 30 12 * 1 1/2 3 3/4 * 5 1/3 2 1/7 * 4 2/3 3 1/3 : 5/18 21/2 : 1 1/2 1 3/8 : 1/8

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