[求助]虚心的急切的请教一个问题-仍然无解继续等待

浅斟低唱

A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight.  What is the value of x ?
(1) y = 10
(2) z = 16

这个题目的意思 是说什么啊
我理解的是 生产X吨混合物含有0.1的G  Y吨有0.02的G  然后生产Z吨含有0.05的G
然后我看有NN的解题思路 有X+Y=Z 我实在看不明白 我想我是不是理解错题目了呢
还请NN继续指点

谢谢大家了

[此贴子已经被作者于2008-9-13 10:39:35编辑过]

浅斟低唱

顶起来 继续等待

sch_qy

我的理解：

x*10%+y*2%=z*5%

x+y=z

=>5x-3y=0

选A

注意combine x with y to produce z

[此贴子已经被作者于2008-9-13 10:50:27编辑过]

sheibiwosha

以下是引用浅斟低唱在2008-9-12 21:47:00的发言：

A contractor combined x tons of a gravel mixture that contained 10 percent gravel G, by weight, with y tons of a mixture that contained 2 percent gravel G, by weight, to produce z tons of a mixture that was 5 percent gravel G, by weight.  What is the value of x ?
(1) y = 10
(2) z = 16

这个题目的意思 是说什么啊
我理解的是 生产X吨混合物含有0.1的G  Y吨有0.02的G  然后生产Z吨含有0.05的G
然后我看有NN的解题思路 有X+Y=Z 我实在看不明白 我想我是不是理解错题目了呢
还请NN继续指点

谢谢大家了

这题上次你问过了是吧

对题理解的不够充分

生产X吨混合物含有0.1的G ← 这理解不对，应该理解为某混合物中含有A物质x吨。然后含有B物质y吨。

然后要产生这种混合物z吨，显然z=x+y

浅斟低唱

谢谢楼上二位

A contractor
        combined
        x tons （of a gravel mixture that contained 10 percent gravel G, by weight）, with y tons （of a mixture that contained 2 percent gravel G, by weight, ）to produce
        z tons （of a mixture that was 5 percent gravel G, by weight.）  What is the value of x ?

这个题意应该这样理解 就对了吧 自己汗一下 理解太差了