作者dodohuang ()
看板GMAT
标题Re: [问题] GWD数学
时间Mon Sep 1 22:15:14 2008
※ 引述《qqopqqop (p )》之铭言：
: A certain company that sells only cars and trucks reported that
: revenues from car sales in 1997 were down 11 percent from 1996 and revenues
: from truck sales in 1997 were up 7 percent from 1996. If total revenues
: from car sales and truck sales in 1997 were up 1 percent from 1996, what is
: the ratio of revenue from car sales in 1996 to revenue from truck sales in
: 1996?
: ans 1:2
: 怎麽算怎麽不对 有人可以帮我一下吗><?
依题意可以列三个方程式
1. 1996 car sales* 0.89= 1997 car sales
2. 1996 truck sales* 1.07= 1997 truck sales
将 1 2 代入 3
3. (1996 car sales + 1996 truck sales)* 1.01= 1997 car sales + 1997 truck sales
= 0.89(1996 car sales)+1.07(97 Trk sales)
把方程式3移过来移过去 过程就不赘述了
可得 0.12(1996 car sales )= 0.06( 1996 truck sales)
故 ratio C:T= 1:2
大概就是这样 希望有帮助到你!
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※ 编辑: dodohuang 来自: 220.133.8.80 (09/01 22:18)
※ 编辑: dodohuang 来自: 220.133.8.80 (09/01 22:18)
1F：→ qqopqqop:感激 09/02 19:15