设30%与20%酒精混合后的体积分数是X%
(X-20)/(30-X)=1/3
X=22.5
45%与22.5%酒精的体积比
(35-22.5)/(45-35)=12.5/10=5/4
45%酒精用量45×5/9=25升
30%酒精用量20×1/4=5升
20%酒精用量20×3/4=15升
设30%与20%酒精混合后的体积分数是X%
(X-20)/(30-X)=1/3
X=22.5
45%与22.5%酒精的体积比
(35-22.5)/(45-35)=12.5/10=5/4
45%酒精用量45×5/9=25升
30%酒精用量20×1/4=5升
20%酒精用量20×3/4=15升