甲数和乙数的比是2:3,乙数和丙数的比是4:5,甲、乙、丙三个数的比是 .
n÷n=. .
= ÷8=1.25=5: = %
= ÷5=0.8=4: = %= 折.
==12÷ = (小数)
16: == ÷5= %= (填小数)=八折.