|
 
- 精华
- 0
- 积分
- 2300
- 经验
- 2300 点
- 威望
- 229 点
- 金钱
- 229 ￥
- 魅力
- 229
|
麻烦大侠们能解释一下这道弱智的DS的过程吗？
41.
Machines X and Y work at their respective constant rates.How many more hours does it take machine Y, working alone, to fill a production order of a certain size than it takes machine X, working alone?
(1) Machines X and Y, working together, fill a production order of this size in two-thirds the time that machine X, working alone, does.
(2) Machine Y, working alone, fills a production order of this size in twice the time that machine X, working alone, does.
我是设他们效率为X,Y，则
1/x+y = 2/3x , 1/y = 2/x
然后解方程吗？发现X=y，之后呢？ |
|
