SOLUTION: one machine can complease a job in 10 minutes if the same job is done by this machine and an older machine working together the two job can be completed in 6 minutes. how long

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Question 1171222: one machine can complease a job in 10 minutes if the same job is done by this machine and an older machine working together the two job can be completed in 6 minutes. how long
Found 3 solutions by MathLover1, josgarithmetic, greenestamps:
Answer by MathLover1(20850) About Me  (Show Source):
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Machine A:+10 minutes
rate 1%2F10 of job in 1 minute
Machine B+%2B++A+=+6+minutes
they do 1%2F6 of the job in 1 minute

Job done by B in 1 minute =
1%2F6+-1%2F10
=%2810-6%29%2F60
=4%2F60
=1%2F15
so machine B+will take 15 minutes to do the same job

Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
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one machine can complease a job in 10 minutes if the same job is done by this machine and an older machine working together the two job can be completed in 6 minutes.
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Maybe this is written better:
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One machine can complete a job in 10 minutes. If the same job is done by this machine and an older machine working together the cross%28two%29 job can be completed in 6 minutes.
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If this is really the way you mean the problem then:
1%2F10%2B1%2Ft=1%2F6
60t%281%2F10%2B1%2Ft%29=%2860t%29%281%2F6%29
6t%2B60=10t
4t=60
highlight%28t=15%29-------------minutes if just the older machine does 1 job alone.

Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


If a formal algebraic solution is not required....

The newer machine can do the job alone in 10 minutes.

So when the two machines together do the job in 6 minutes, the newer machine does 6/10 = 3/5 of the job.

That means in those 6 minutes the older machine does 2/5 of the job.

2/5 of the job in 6 minutes means the older machine can do the whole job alone in (5/2)*6 = 15 minutes.