document.write( "Question 698556: A father can do a job in a certain cumber of hours. His son takes twice as long as to do the job. Working together, they can do the job in 6 hours. How many hours does it take the father to do the job alone?
\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #430815 by Alan3354(69443)\"\" \"About 
You can put this solution on YOUR website!
A father can do a job in a certain cumber of hours. His son takes twice as long as to do the job. Working together, they can do the job in 6 hours. How many hours does it take the father to do the job alone?
\n" ); document.write( "------------------
\n" ); document.write( "The father works as fast as 2 sons, equal to 3 sons taking 6 hours
\n" ); document.write( "--> each son takes 18 hours
\n" ); document.write( "--> father takes 9 hours.
\n" ); document.write( "==========================
\n" ); document.write( "The hard way:
\n" ); document.write( "The son takes x hours alone
\n" ); document.write( "--> the son does 1/x of the job per hour
\n" ); document.write( "The father does 2/x per hour
\n" ); document.write( "Together, they do 1/x + 2/x per hour = 1/6
\n" ); document.write( "1/x + 2/x = 1/6
\n" ); document.write( "1 + 2 = x/6
\n" ); document.write( "x/6 = 3
\n" ); document.write( "x = 18 hours for the son
\n" ); document.write( "--> 9 hours for the father
\n" ); document.write( " \n" ); document.write( "
\n" );