Question 1146094
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Both of the responses from other tutors show variations of the standard process for solving "working together" problems like this.<br>
Here is a solution by an alternative method that many students find easier.<br>
(1) The times needed for the two machines to produce 7200 cans are 180 minutes and 360 minutes.
(2) The least common multiple of 180 and 360 is 360; consider what the two machines can do in 360 minutes.
(3) In 360 minutes, the newer machine can produce 2*7200 = 14400 cans; in that same time the older machine can produce 7200 cans.  So in 360 minutes the two machines can produce 14400+7200 = 21600 cans.
(4) Since 21600 = 3*7200, the time required for the two machines together to produce 7200 cans is 360/3 = 120 minutes.<br>