document.write( "Question 266020: Two brothers are digging a drainage ditch for a french drain around their home. The ditch is to be 2 feet deep, 1 foot wide, and 40 feet long. The older brother can dig the ditch in 14 hours. The younger brother can dig the ditch in 17 hours. How long will the two brothers working together take to dig the ditch? (Round your answer to the nearest tenth.) \n" ); document.write( "
Algebra.Com's Answer #195506 by ptaylor(2198)\"\" \"About 
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\n" ); document.write( "Let x=amount of time it takes the two brothers working together
\n" ); document.write( "Then the two bros dig at the rate of 1/x ditch per hour
\n" ); document.write( "Older bro digs at the rate of 1/14 ditch per hour
\n" ); document.write( "The younger bro digs at the rate of 1/17 ditch per hour
\n" ); document.write( "The two bros dig at he rate of 1/14 + 1/17 ditch per hour
\n" ); document.write( "So, our equation to solve is:
\n" ); document.write( "1/14 + 1/17=1/x Multiply each term by 14*17*x
\n" ); document.write( "17x+14x=238
\n" ); document.write( "31x=238
\n" ); document.write( "x=238/31
\n" ); document.write( "x=7.677 hours=7.7 hours---answer\r
\n" ); document.write( "\n" ); document.write( "CK
\n" ); document.write( "In 238/31 hours, older bro digs (1/14)*(238/31) =17/31 of the ditch
\n" ); document.write( "In 238/31 hours the younger bro digs (1/17)*(238/31) =14/31 of the ditch
\n" ); document.write( "17/31 + 14/31=1 (1 ditch, that is)
\n" ); document.write( "1=1\r
\n" ); document.write( "\n" ); document.write( "Hope this helps-ptaylor
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