document.write( "Question 667145: A tank can be filled by two pipes separately in 10 and 15 minutes respectively.
\n" ); document.write( "When a third pipe is used simultaneously with the first two pipes, the tank can be filled in 4 minutes. How long would it take the third pipe alone to fill the tank? \n" ); document.write( "
Algebra.Com's Answer #414817 by lwsshak3(11628)\"\" \"About 
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A tank can be filled by two pipes separately in 10 and 15 minutes respectively.
\n" ); document.write( "When a third pipe is used simultaneously with the first two pipes, the tank can be filled in 4 minutes. How long would it take the third pipe alone to fill the tank
\n" ); document.write( "**
\n" ); document.write( "let x= How long would it take the third pipe alone to fill the tank
\n" ); document.write( "1/10=work rate of 1st pipe
\n" ); document.write( "1/15=work rate of 2nd pipe
\n" ); document.write( "1/x=work rate of 3rd pipe
\n" ); document.write( "1/4=work rate of 3 pipes working together
\n" ); document.write( "..
\n" ); document.write( "sum of individual work rates=work rate working together
\n" ); document.write( "1/10+1/15+1/x=1/4
\n" ); document.write( "1/x=1/4-1/10-1/15
\n" ); document.write( "=15/60-6/60-4/60
\n" ); document.write( "=5/60
\n" ); document.write( "1/x=1/12
\n" ); document.write( "x=12
\n" ); document.write( "How long would it take the third pipe alone to fill the tank=12 min \n" ); document.write( "
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