document.write( "Question 532541: Both inlet and outlet pipes to a cider barrel were mistakenly left open. Nevertheless, the barrel filled in 12 hours. With only the outlet pipe open, a full barrel of cider can be emptied in 1 hour more than the time to fill an empty barrle with only the inlet pipe open. How long would draining a full barrel of cider take with the outlet pipe open and the inlet pipe closed? \n" ); document.write( "
Algebra.Com's Answer #350863 by ankor@dixie-net.com(22740)\"\" \"About 
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Both inlet and outlet pipes to a cider barrel were mistakenly left open.
\n" ); document.write( " Nevertheless, the barrel filled in 12 hours.
\n" ); document.write( " With only the outlet pipe open, a full barrel of cider can be emptied in 1 hour more than the time to fill an empty barrel with only the inlet pipe open.
\n" ); document.write( " How long would draining a full barrel of cider take with the outlet pipe open and the inlet pipe closed?
\n" ); document.write( ":
\n" ); document.write( "Let t = time required by the outlet pipe with inlet closed, to drain the barrel
\n" ); document.write( "then
\n" ); document.write( "(t-1) = time required by the inlet pipe to fill the barrel (outlet closed)
\n" ); document.write( ":
\n" ); document.write( "let a full tank = 1
\n" ); document.write( ":
\n" ); document.write( "\"12%2F%28%28t-1%29%29\" - \"12%2Ft\" = 1
\n" ); document.write( "multiply by t(t-1) to clear the denominators, results:
\n" ); document.write( "12t - 12(t-1) = t(t-1)
\n" ); document.write( "12t - 12t + 12 = t^2 - t
\n" ); document.write( "Arrange as a quadratic equation
\n" ); document.write( "0 = t^2 - t - 12
\n" ); document.write( "Factors to
\n" ); document.write( "(t-4)(t+3) = 0
\n" ); document.write( "the positive solution is all we want here
\n" ); document.write( "t = 4 hrs to drain the tank with the inlet closed
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "\"12%2F3\" - \"12%2F4\" =
\n" ); document.write( "4 - 3 = 1
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