document.write( "Question 273718: An experienced bricklayer can work twice as fast as an apprentice bricklayer. After they worked on a job for 8 hours, the experienced bricklayer quit. The apprentice required 12 more hours to finish the job. How long would it take the experienced bricklayer, working alone, to do the job? \n" ); document.write( "

Algebra.Com's Answer #199973 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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An experienced bricklayer can work twice as fast as an apprentice bricklayer.
\n" ); document.write( " After they worked on a job for 8 hours, the experienced bricklayer quit.
\n" ); document.write( " The apprentice required 12 more hours to finish the job.
\n" ); document.write( " How long would it take the experienced bricklayer, working alone, to do the job?
\n" ); document.write( ":
\n" ); document.write( "Let x = time required by an experienced bricklayer alone
\n" ); document.write( "then
\n" ); document.write( "2x = time required by an apprentice alone
\n" ); document.write( ":
\n" ); document.write( "Let the completed job = 1
\n" ); document.write( ":
\n" ); document.write( "Experienced worked for 8 hrs
\n" ); document.write( "Apprentice worked 8 + 12 = 20 hrs
\n" ); document.write( ":
\n" ); document.write( " $\"8%2Fx\"$ + $\"20%2F%282x%29\"$ = 1
\n" ); document.write( "which is:
\n" ); document.write( " $\"8%2Fx\"$ + $\"10%2Fx\"$ = 1
\n" ); document.write( "multiply byx, results:
\n" ); document.write( "8 + 10 = x
\n" ); document.write( "x = 18 hrs, the experience guy working alone
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "Check solution
\n" ); document.write( " $\"8%2F18\"$ + $\"20%2F%2836%29\"$ = 1
\n" ); document.write( ".44 + .56 = 1 \n" ); document.write( "

\n" );