0.700 1.450 30.500 0.2050 10.6060 0.0600 306.040 205.000. .
=20: = %=2÷5= 成.
甲数和乙数的比是2:3,则甲占甲乙两数和的. .
13:2= ÷ = :4=39: .
12: =0.6==6÷ = %
÷20=6: == %= 成=0.15.