SOLUTION: A full bathtub is empty at an average rate of 10 minutes. It will fill up to full at an average rate of 8 minutes if the plug is in. How long will it take to fill up to full if the
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-> SOLUTION: A full bathtub is empty at an average rate of 10 minutes. It will fill up to full at an average rate of 8 minutes if the plug is in. How long will it take to fill up to full if the
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Question 941794: A full bathtub is empty at an average rate of 10 minutes. It will fill up to full at an average rate of 8 minutes if the plug is in. How long will it take to fill up to full if the plug is removed and the tap is turned on?
Please provide solution steps. Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Rate of emptying:
( 1 tub ) / ( 10 min )
Rate of filling with plug in:
( 1 tub ) / ( 8 min )
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What you have to realize at this point is
that the rate of filling is greater than the
rate of emptying, so if you pull the plug
out, the tub will EVENTUALLY fill up.
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Let = the time in minutes for the tub
to fill if the tap is on and the plug is removed
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Add the rate of filling
Subtract the rate of emptying
Make that equal to:
( 1 tub filled ) / ( t min ) =
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Multiply both sides by
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In 40 min the tub will fill if the tap is
on and the plug is removed
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check:
OK
