2. 外语
  3. Working alone at its constant rate, machine A takes 3 hours to produce a batch of identical computer parts. Working alone at its

Working alone at its constant rate, machine A takes 3 hours to produce a batch of identical computer parts. Working alone at its

admin2018-12-14  136
问题 Working alone at its constant rate, machine A takes 3 hours to produce a batch of identical computer parts. Working alone at its constant rate, machine B takes 2 hours to produce an identical batch of parts. How long will it take the two machines, working simultaneously at their respective constant rates, to produce an identical batch of parts?
选项
答案6/5 hours, or 1 hour 12 minutes
解析 Since machine A takes 3 hours to produce a batch, machine A can produce 1/3 of the batch in 1 hour. Similarly, machine B can produce - of the batch in 1 hour. If we let x represent the number of hours it takes both machines, working simultaneously, to produce the batch, then the two machines will produce - of the job in 1 hour. When the two machines work together, adding their individual production rates, 1/3 and 1/2, gives their combined production rate 1/x. Therefore,

Thus, working together, the machines will take 6/5 hours, or 1 hour 12 minutes, to produce a batch of parts.
转载请注明原文地址:https://kaotiyun.com/show/3MkO777K
本试题收录于： GRE QUANTITATIVE题库GRE分类
0

GRE QUANTITATIVE

GRE

相关试题推荐
随机试题
最新回复(0)