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A company has two types of machines, type R and type S. Operating at a
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27 Jun 2022, 20:25
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A company has two types of machines, type R and type S. Operating at a constant rate, a machine of type R does a certain job in 36 hrs and a machine of type S does the same job in 18 hours. If the company used the same number of each type of machine to do the job in 2 hours, how many machines of type R were used?
Re: A company has two types of machines, type R and type S. Operating at a
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11 Jul 2022, 23:46
GeminiHeat wrote:
A company has two types of machines, type R and type S. Operating at a constant rate, a machine of type R does a certain job in 36 hrs and a machine of type S does the same job in 18 hours. If the company used the same number of each type of machine to do the job in 2 hours, how many machines of type R were used?
A. 3 B. 4 C. 6 D. 9 E. 12
I don't understand the question stem in the first place. Might anyone be able to help me?
Re: A company has two types of machines, type R and type S. Operating at a
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11 Jul 2022, 23:56
1
Expert Reply
Rate of A - 136 job/hour, rate of x machines of A - 136x job/hour; Rate of B - 118 job/hour, rate of x machines of B - 118x job/hour, (same number of each type);
Remember that we can sum the rates, hence combined rate of A and B is 136x+118x=336x=112x job/hour.
We are told that together equal number (x in our case) of machines A and B can do the job (1 job) in 2 hours --> Time∗Rate=2∗112x=1=Job --> x=6.
Re: A company has two types of machines, type R and type S. Operating at a
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31 Jan 2024, 17:29
Hello from the GRE Prep Club BumpBot!
Thanks to another GRE Prep Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).
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Re: A company has two types of machines, type R and type S. Operating at a [#permalink]