document.write( "Question 817743: A and B can do a piece of work in 12 days , B and C can do it in 15 days and C and A can do it in 20 days . A alone can do it in \n" ); document.write( "

Algebra.Com's Answer #492530 by richwmiller(17219) $\"\"$ $\"About$

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12/a+12/b=1,
\n" ); document.write( "15/b+15/c=1,
\n" ); document.write( "20/a+20/c=1
\n" ); document.write( "a = 30, b = 20, c = 60
\n" ); document.write( "a can do it alone in 30 days
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