SOLUTION: A chemistry experiment requires that a vacuum be created in a chamber. A small vacuum pump requires 30 seconds to evacuate the chamber. The large vacuum pump requires 20 seconds to

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Question 1033131: A chemistry experiment requires that a vacuum be created in a chamber. A small vacuum pump requires 30 seconds to evacuate the chamber. The large vacuum pump requires 20 seconds to evacuate. Find the time required for both pumps working together to evacuate the chamber.
Found 2 solutions by stanbon, ikleyn:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
A chemistry experiment requires that a vacuum be created in a chamber. A small vacuum pump requires 30 seconds to evacuate the chamber. The large vacuum pump requires 20 seconds to evacuate. Find the time required for both pumps working together to evacuate the chamber.
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small pump rate:: 1/30 job/sec
large pump rate:: 1/20 job/sec
---
together rate:: 1/x job/sec
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Equation:
rate + rate = together rate
1/30 + 1/20 = 1/x
30x + 20x = 30*20
50x = 600
x = 12 sec/job (time to do the job together)
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Cheers,
Stan H.
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Answer by ikleyn(52772) About Me  (Show Source):
You can put this solution on YOUR website!
.
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