把一个数按5:4:3分成甲、乙、丙三部分,如果丙是12,原来的数是 ,甲数是 .
:20==3: =0.75= %
0.125== :16=5÷ .
= :24=0.5= ÷8=.
6÷ == %== : .
= %=6: == (写小数)