document.write( "Question 590666: A tank has supply pipe A and an exhaust pipe B. The pipe A takes 4 minutes less to fill a tank than the pipe B takes to empty it. When both are open, the tank is filled in 24 minutes. Find the time needed for pipe A to fill the tank when pipe B is closed. \n" ); document.write( "
Algebra.Com's Answer #375219 by lwsshak3(11628)\"\" \"About 
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A tank has supply pipe A and an exhaust pipe B. The pipe A takes 4 minutes less to fill a tank than the pipe B takes to empty it. When both are open, the tank is filled in 24 minutes. Find the time needed for pipe A to fill the tank when pipe B is closed.
\n" ); document.write( "**
\n" ); document.write( "let x=minutes pipe B takes to empty tank
\n" ); document.write( "1/x=pipe B work rate
\n" ); document.write( "x-4=minutes pipe A takes to fill tank
\n" ); document.write( "1/(x-4)=Pipe A work rate
\n" ); document.write( "..
\n" ); document.write( "In 24 minutes:
\n" ); document.write( "24/(x-4)-24/x=100%
\n" ); document.write( "24x-24x+96=x(x-4)=x^2-4x
\n" ); document.write( "x^2-4x-96=0
\n" ); document.write( "(x-12)(x+8)=0
\n" ); document.write( "x=-8 (reject, x>0)
\n" ); document.write( "x=12
\n" ); document.write( "x-4=8
\n" ); document.write( "ans:
\n" ); document.write( "Pipe A alone fills tank in 8 minutes (When Pipe B is closed) \n" ); document.write( "
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