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[Problem Solving]

试题详情

题目:

Working simultaneously at their respective constant rates, Machines A and B produce 800 nails in x hours. Working alone at its constant rate, Machine A produces 800 nails in y hours. In terms of x and y, how many hours does it take Machine B, working alone at its constant rate, to produce 800 nails?

选项:

A、 $$\frac{x}{x+y}$$
B、 $$\frac{y}{x+y}$$
C、 $$\frac{xy}{x+y}$$
D、 $$\frac{xy}{x-y}$$
E、 $$\frac{xy}{y-x}$$

答案:

E

提问:

为啥我算出来是xy/800y-x

解答:

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阅读769
解答: 徐小梅

提问:

为啥我算出来是xy/800y-x

解答:

点赞0
阅读770
解答: 徐小梅老师

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