3 1/9 : 2 1/3 = 28/9 : 7/3 = 28/9 * 3/7 = 4/3
16/21 : 20/49 = 16/21 * 49/20 = 4/3 * 7/5 = 28/15 = 1 13/15
3 2/9 : 2 = 29/9 : 2/1 = 29/9 * 1/2 = 29/18 = 1 11/18
1 2/3 : 2 1/2 = 5/3 : 5/2 = 5/3 * 2/5 = 2/3
17/30 : 34/75 = 17/30 * 75/34 = 1/6 * 15/2 = 15/12 = 1 3/12 = 1 1/4
3 : 1 2/3 = 3/1 : 5/3 = 3/1 * 3/5 = 9/5 = 1 4/5
1 5/7 : 3 3/4 = 12/7 : 15/4 = 12/7 * 4/15 = 4/7 * 4/5 = 16/35
15/28 : 40/49 = 15/28 * 49/40 = 3/4 * 7/8 = 21/32
1 5/7 : 4 = 12/7 : 4/1 = 12/7 * 1/4 = 3/7