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At a certain factory, each of Machines A, B, and C is periodically on

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At a certain factory, each of Machines A, B, and C is periodically on [#permalink] New post   16 Sep 2021, 21:31
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At a certain factory, each of Machines A, B, and C is periodically on for exactly 1 minute and periodically off for a fixed number of consecutive minutes as shown in the table above. When Machine A is on it uses 15 units of power every 18th minute, Machine B uses 18 units of power every 15th minute, and Machine C uses 12 units of power every 12th minute. The factory has a backup generator that operates only when the total power usage of the 3 machines exceeds 30 units of power.

Quantity A
Quantity B
Time interval (in min.) between consecutive times the backup generator begins to operate
180


A. Quantity A is greater
B. Quantity B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
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Re: At a certain factory, each of Machines A, B, and C is periodically on [#permalink] New post   17 Sep 2021, 05:45
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Though there are 3 machines, just machine A and B running concurrently can consume more than 30 units of power. So LCM of times intervals of A and B is LCM(18,15) = 90.

Answer is B) Quantity B is larger.
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At a certain factory, each of Machines A, B, and C is periodically on [#permalink] New post   03 Mar 2023, 04:10
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Firstly the problem as about the Total time interva between the Machine A and the backup.
Let's add the total power consumed for the minutes of A,B and C.It is 15+18_12 = 45 units/However the machine backup works as soon as 30 units are are consumed. We formulate 2 equations :
45 UNITS = 42 minutes. 30 units = " x". so simplify gives a value of 28minutes which is way lesser than quantity "180". so "180" is greater.
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Re: At a certain factory, each of Machines A, B, and C is periodically on [#permalink] New post   12 Sep 2025, 21:49
Hello from the GRE Prep Club BumpBot!

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Re: At a certain factory, each of Machines A, B, and C is periodically on [#permalink]
12 Sep 2025, 21:49
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