document.write( "Question 306164: Lynn can paint room in 40 min.
\n" ); document.write( "Jeff in 60 min.
\n" ); document.write( "How long if both paint together? Not sure what type of problem this is. fxn? \n" ); document.write( "

Algebra.Com's Answer #219172 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

You can put this solution on YOUR website!
Lynn can paint room in 40 min .Jeff in 60 min. How long if both paint together?
\n" ); document.write( ":
\n" ); document.write( "This is a typical shared work problem.
\n" ); document.write( ":
\n" ); document.write( "Let t = time required when they work together (in minutes)
\n" ); document.write( ":
\n" ); document.write( "Let the completed job = 1 (a painted room)
\n" ); document.write( ";
\n" ); document.write( "Each person will paint a fraction of the room, the two fractions add up to 1
\n" ); document.write( ":
\n" ); document.write( " $\"t%2F40\"$ + $\"t%2F60\"$ = 1
\n" ); document.write( "We can clear the fractions by multiplying 120, resulting in:
\n" ); document.write( "3t + 2t = 120
\n" ); document.write( ":
\n" ); document.write( "5t = 120
\n" ); document.write( "t = $\"120%2F5\"$
\n" ); document.write( "t = 24 minutes working together
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "We can prove that
\n" ); document.write( " $\"24%2F40\"$ + $\"24%2F60\"$ = 1
\n" ); document.write( "reduce the fractions
\n" ); document.write( " $\"6%2F10%29\"$ + $\"4%2F10\"$ = 1
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "This is a good method for most shared work problems.
\n" ); document.write( " \n" ); document.write( "

\n" );