1/2=2/4
6/8=3/4
1/2＜6/8
4/12=1/3
5/20=1/4
4/12＞5/20
10/16=5/8
9/24=3/8
10/16＞9/24
12/15=4/5
20/25=4/5
12/15=20/25
12/16=3/4
21/35=3/5
12/16＞21/35
25/60=5/12
30/72=5/12
25/60=30/72
8/18=4/9
18/81=2/9
8/18＞18/81