一、求比值。
$25:0.5=$
$\frac{1}{3}:\frac{1}{4}=$
$0.3:\frac{9}{7}=$
$\frac{1}{7}:\frac{5}{14}=$
$12.6:0.4=$
$3:0.12=$
$35:105=$
$0.25:1=$
$\frac{3}{10}:\frac{7}{5}=$
$\frac{4}{3}:\frac{5}{6}=$
$12:2.4=$
$\frac{3}{4}:6=$

1. $25:0.5=50$
2. $\frac{1}{3}:\frac{1}{4}=\frac{4}{3}$
3. $0.3:\frac{9}{7}=\frac{7}{30}$
4. $\frac{1}{7}:\frac{5}{14}=\frac{2}{5}$
5. $12.6:0.4=\frac{63}{2}$
6. $3:0.12=25$
7. $35:105=\frac{1}{3}$
8. $0.25:1=\frac{1}{4}$
9. $\frac{3}{10}:\frac{7}{5}=\frac{3}{14}$
10. $\frac{4}{3}:\frac{5}{6}=\frac{8}{5}$
11. $12:2.4=5$
12. $\frac{3}{4}:6=\frac{1}{8}$

二、把下面各比化成最简整数比。
$8.4:3.6=(\quad):(\quad)$
$\frac{1}{7}:\frac{1}{49}=(\quad):(\quad)$
$72:96=(\quad):(\quad)$
$4.2:\frac{3}{4}=(\quad):(\quad)$
$1.6:2.5=(\quad):(\quad)$
$\frac{5}{8}:\frac{15}{32}=(\quad):(\quad)$
$3.6:48=(\quad):(\quad)$
$\frac{15}{4}:2.5=(\quad):(\quad)$

1. $8.4:3.6=7:3$
2. $\frac{1}{7}:\frac{1}{49}=7:1$
3. $72:96=3:4$
4. $4.2:\frac{3}{4}=28:5$
5. $1.6:2.5=16:25$
6. $\frac{5}{8}:\frac{15}{32}=4:3$
7. $3.6:48=3:40$
8. $\frac{15}{4}:2.5=3:2$

三、根据比例的基本性质，在括号里填合适的数。
$4:3=8:(\quad)$
$1.2:8=3.6:(\quad)$
$(\quad):6=14:3$
$0.8:0.5=(\quad):4$
$1.5:3=(\quad):9$
$0.2:0.1=(\quad):4$
$2:(\quad)=6:3.6$
$1:(\quad)=3:1.5$
$4.8:(\quad)=1.2:2.4$
$\frac{1}{3}:\frac{1}{5}=\frac{1}{6}:(\quad)$
$(\quad):\frac{3}{8}=5:3$
$\frac{4}{5}:\frac{4}{15}=\frac{5}{8}:(\quad)$
$0.25:(\quad)=\frac{5}{2}:30$
$(\quad):\frac{10}{7}=35:10$
$2:5=\frac{2}{9}:(\quad)$
$\frac{4}{5}:2=8:(\quad)$
$\frac{3}{20}:\frac{3}{2}=(\quad):90$
$\frac{1}{20}:(\quad)=1:4$

1. $4:3=8:6$
2. $1.2:8=3.6:24$
3. $28:6=14:3$
4. $0.8:0.5=6.4:4$
5. $1.5:3=4.5:9$
6. $0.2:0.1=8:4$
7. $2:1.2=6:3.6$
8. $1:0.5=3:1.5$
9. $4.8:9.6=1.2:2.4$
10. $\frac{1}{3}:\frac{1}{5}=\frac{1}{6}:\frac{1}{10}$
11. $\frac{5}{8}:\frac{3}{8}=5:3$
12. $\frac{4}{5}:\frac{4}{15}=\frac{5}{8}:\frac{5}{24}$
13. $0.25:3=\frac{5}{2}:30$
14. $5:\frac{10}{7}=35:10$
15. $2:5=\frac{2}{9}:\frac{5}{9}$
16. $\frac{4}{5}:2=8:20$
17. $\frac{3}{20}:\frac{3}{2}=9:90$
18. $\frac{1}{20}:\frac{1}{5}=1:4$