甲圆半径是2厘米,乙圆半径是3厘米.甲、乙两圆周长比 ,比值是 ;面积比是 ,比值是 .
0.75=9÷ ==18÷ =.
3:8== ÷ =12: = :24= 小数.
0.75= %=6÷ = :12.
1.75=7÷ ==21÷ =.
%= ÷15==0.6.