Question
It takes Machine Q and Machine B 10 minutes to print a total of 480 copies of posters. Machine Q can print 20 copies of posters in one minute. How many copies of posters can Machine R print per minute?
2 m

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It takes Machine Q and Machine B 10 minutes to print a total of 480 copies of posters. Machine Q can print 20 copies of posters in one minute. How many copies of posters can Machine R print per minute?