2:1/7; 4:2/3; 3:1/2; 1:2/7; 1:1/4
2:1/7=2/1*7/1=14; ////4:2/3=4/1*3/2=6; ///3:1/2=3/1*2/1=6; ////1:2/7=1/1*7/2=3 1/2; 1:1/4=1/1*4/1=4