2/3:5/7,1/4:1/2,2/5:2/3,3/4:1/2,5/6:7/12
2/3 : 5/7 = 2/3 * 7/5 = 14/15 1/4 : 1/2 = 1/4 * 2/1 = 2/4 = 1/2 2/5 : 2/3 = 2/5 * 3/2 = 3/5 3/4 : 1/2 = 3/4 * 2/1 = 3/2 = 1 1/2 5/6 : 7 /12 = 5/6 * 12/7 = 10/7 = 1 3/7