(二七区)如图是一个箭靶,二人比赛射箭.甲射了5箭,一箭落入A圈,三箭落入B圈,一箭落入C圈,共得30环;乙也射了5箭,两箭落入A圈,一箭落入B圈,两箭落入C圈,也得30环.则B圈是 环.
3:8== ÷ =12: = :24= 小数.
0.75= %=6÷ = :12.
1.75=7÷ ==21÷ =.
%= ÷15==0.6.
1÷4== %= (填小数)