3/4*2/5; 3/5* 20/21; 6*4/3; 3/8*10/11; 3/10*15; 5/4*5

3/4*2/5=3/2*1/5=3/103/5*20/21=1/1*4/7=4/76*4/3=2*4=83/8*10/11=3/4*5/11=15/443/10*15=3/2*3=9/2=4 1/25/4*5=25/4=6 1/4