document.write( "Question 309889: Pipes A and B can fill a tank in 45 minutes when used together. Alone, pipe A can fill the tank in one hour. How long would it take to fill the tank if only pipe B is used? \n" ); document.write( "
Algebra.Com's Answer #221667 by ankor@dixie-net.com(22740)\"\" \"About 
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Pipes A and B can fill a tank in 45 minutes when used together.
\n" ); document.write( " Alone, pipe A can fill the tank in one hour.
\n" ); document.write( " How long would it take to fill the tank if only pipe B is used?
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\n" ); document.write( "Change 1 hr to 60 min
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\n" ); document.write( "Let b = time for B to fill it alone
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\n" ); document.write( "Let the completed job = 1 (a full tank)
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\n" ); document.write( "\"45%2F60\" + \"45%2Fb\" = 1
\n" ); document.write( "Reduce the fraction
\n" ); document.write( "\"3%2F4\" + \"45%2Fb\" = 1
\n" ); document.write( "multiply by 4b, results:
\n" ); document.write( "3b + 4(45) = 4b
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\n" ); document.write( "3b + 180 = 4b
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\n" ); document.write( "180 = 4b - 3b
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\n" ); document.write( "180 = b
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\n" ); document.write( "B can fill the tank alone in 180 minutes
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\n" ); document.write( "Check:
\n" ); document.write( "45/60 + 45/180 =
\n" ); document.write( ".75 + .25 = 1\r
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