急.......酒精.水混合的數學題 - 酒精

By Brianna
at 2007-01-18T00:00
at 2007-01-18T00:00
Table of Contents
酒精.水混合後若干公升.其中酒精65%.再加上15公升的酒精.濃度變為80%.求原來酒精.水為多少公升.
Tags:
酒精
All Comments

By Candice
at 2007-01-22T15:07
at 2007-01-22T15:07
設原有「酒精溶液」x公升
所以酒精有0.65x公升
加上15公升的酒精之後,式子就會變成:
(0.65x+15)/(x+15)=80/100
把式子交叉相乘之後,可求得x=20
酒精佔65%,所以酒精有0.65*20=13公升
水有20-13=7公升

By Charlotte
at 2007-01-19T18:32
at 2007-01-19T18:32
酒精為0.65x
加上15公升
(x+15)*0.8=0.65x
=>0.8x+12=0.65x
=>12=0.15x
=>x=80
80*0.65=52
80-52=28
答:酒精為52公升水為28公升

By Kumar
at 2007-01-21T06:33
at 2007-01-21T06:33
水Y公升
原本:
X/Y=65/100 => 100X=65Y (第1式)
加15公升的酒精後:
(X+15)/Y=80/100 =>100X+1500=80Y (第2式)
兩個式子相減 第2式- 第1式 => 1500=15Y Y=100 再代回去 第1式 X=65 所以 酒精原本65公升 水原本 100公升
Related Posts
有關酒精掛載的問題??CLUBBOX??

By Rebecca
at 2007-01-17T00:00
at 2007-01-17T00:00
坐月子喝黑豆酒比較好?還是要喝黑豆水?

By Yedda
at 2007-01-16T00:00
at 2007-01-16T00:00
衣服滴到峰膠該怎麼清潔乾淨

By Gary
at 2007-01-16T00:00
at 2007-01-16T00:00
台灣啤酒和高梁酒之類的酒類哪一種對身體傷害較大!??

By Gary
at 2007-01-16T00:00
at 2007-01-16T00:00
喝麻油雞會醉

By Mason
at 2007-01-15T00:00
at 2007-01-15T00:00