SOLUTION: One machine can seal 360 packages/hr, an older machine can seal 140 packages/hr. How many minutes will the two machines working together take to seal a total of 700 packages? ans

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Question 468942: One machine can seal 360 packages/hr, an older machine can seal
140 packages/hr. How many minutes will the two machines working together take to seal a total of 700 packages? answers: 48, 72, 84, 90, 108
Found 2 solutions by stanbon, Edwin McCravy:
Answer by stanbon(75887)   (Show Source): You can put this solution on YOUR website!
one machine can seal 360 packages/hr, an older machine can seal 140packages/hr. how amny minytes together will the two machines working together take to seal a total of 700 packages? answers:48,72,84,90,1-8
----
rate + rate = together rate
360 + 140 = x packages/hour
x = 500 packages/hour
----
time = 1/500 hr/package
--------
Time for 700 packages = 700(1/500) = 7/5 hr = 1 hr. 24 minutes or 84 minutes
===================
Cheers,
Stan H.

Answer by Edwin McCravy(20060)   (Show Source): You can put this solution on YOUR website!
We add their rates to get their combined rate:

360 + 140 = 500

1 hour is 60 minutes, so the problem is now:

If they can seal 500 packages in 60 minutes, how many
minutes will it take them to seal 700 packages?

We set up the proportion: 

500 packages     700 packages
------------  = --------------
 60 minutes        x minutes

Cross multiply

         500x = 42000

            x =  = 84 minutes


Edwin
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