GMAT Practice Question: Working at a constant rate, a copy machine makes 20 copies of a one-page document per minute. If...
Question
Working at a constant rate, a copy machine makes 20 copies of a one-page document per minute. If the machine works at this constant rate, how many hours does it take to make 4,800 copies of a one-page document?
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Topics: word problems, translations, conversions, rates
Solution
Step 1
We define the variables for the total number of copies and the time in minutes.
C = number of copies T = time in minutes
Step 2
We translate "a copy machine makes 20 copies of a one-page document per minute" into a rate equation.
C = 20T
Step 3
We translate "4,800 copies" as the total number of copies to be produced.
C = 4800
Step 4
We set up the equation relating copies to time and solve for T.
4800 = 20T T = 4800/20
Step 5
We simplify to find the time in minutes.
T = 240
Step 6
We convert the time from minutes to hours by dividing by 60.
H = T/60
Step 7
We calculate the number of hours.
H = 240/60 = 4
Answer
It takes 4 hours, so the correct answer is A.
