1.2:2.4=1.8:3.62.4:1.2=3.6:1.81.8:3:6=1.2:2.43.6:1.8=2.4:1.23.6:2.4=1.8:1.2
1.2:2.4=1.8:3.6 1.2:1.8=2.4:3.6