1）3.2:4 3:(5/7) 25%:2
=32/40 =21：5 =0.25/2
=4/5.=1/8.
2)100:25 6:0.06 (2/3):(2/9)
=4:1.=600/6 =（6/9）):(2/9)
=100:1 =3:1