合唱队男生和女生人数的比是3:2,若合唱队有30人,则女生有12人. .(判断对错)
÷=== :50=.
12: =0.375=45÷ = :56=.
15:90= %==6÷ = :12.
=:0.5= ÷ .
:8===9÷ =27: .