document.write( "Question 767486: A water tank can be filled by an inlet pipe in t = 7 hours. It takes twice that long for the outlet pipe to empty the tank. How long will it take to fill the tank if both pipes are open? \n" ); document.write( "
Algebra.Com's Answer #467656 by josgarithmetic(39620)\"\" \"About 
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Two rates are these:\r
\n" ); document.write( "\n" ); document.write( "Fill, \"1%2F7\" tank per hour.
\n" ); document.write( "Empty, \"-1%2F14\" tank per hour
\n" ); document.write( "Combined Rates for each pipe: \"1%2F7%2B%28-1%2F14%29=2%2F14-1%2F14=highlight%281%2F14%29\" tank per hour.
\n" ); document.write( "The reciprocal of this is the rate to fill as HOURs per TANK.
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