document.write( "Question 608078: Tom is painting the set for a school play. Working alone, he could finish the job in 12 hours. His friend Brad could paint the set in 8 hours. Tom and Brad begin working together, but after 3 hours, Brad leaves. How many more hours will tom need to work to finish the set? \n" ); document.write( "

Algebra.Com's Answer #383036 by ewatrrr(24785) $\"\"$ $\"About$

You can put this solution on YOUR website!

 
\n" );
document.write( "Hi
\n" );
document.write( "Tom in 12 hours...His friend Brad could paint the set in 8 hours
\n" );
document.write( "Let x represent time to finish the Entire set together
\n" );
document.write( "Per Hour KEY:
\n" );
document.write( " 1/12 + 1/8 = 1/x
\n" );
document.write( "   8x + 12x = 96
\n" );
document.write( "       20x = 96
\n" );
document.write( "         x = 4.8 hr, 
\n" );
document.write( "% of work w done together in 3 hr
\n" );
document.write( "         1/4.8 = w/3
\n" );
document.write( "            3 = 4.8w
\n" );
document.write( "            3/4.8 = .625 = w
\n" );
document.write( "How many more hours h will tom need to work to finish the set
\n" );
document.write( " 1/12 = .625/h
\n" );
document.write( "   h = 12(.625)= 7.5 more hours \n" );
document.write( "

\n" );