document.write( "Question 1192756: A mechanic can fix a car twice as fast as his helper. One day, the mechanic and helper worked together for 2 hours. Then the mechanic got called away, and the helper needed 1 more hour to finish the job. How long does it take the helper, working alone, to fix the car? \n" ); document.write( "

Algebra.Com's Answer #824653 by ikleyn(52781) $\"\"$ $\"About$

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\n" ); document.write( "A mechanic can fix a car twice as fast as his helper.
\n" ); document.write( "One day, the mechanic and helper worked together for 2 hours.
\n" ); document.write( "Then the mechanic got called away, and the helper needed 1 more hour to finish the job.
\n" ); document.write( "How long does it take the helper, working alone, to fix the car?
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document.write( "Let x be the rate of work of the helper; then the rate of work of the mechanic is 2x.\r\n" );
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document.write( "In 2 hours, the helper will do  2x parts of work; the mechanic will do 2*(2x) = 4x parts of work.\r\n" );
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document.write( "The total job equation is\r\n" );
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document.write( "    2x + 4x + x = 1,\r\n" );
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document.write( "or\r\n" );
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document.write( "        7x = 1,\r\n" );
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document.write( "which implies  x = 1/7.\r\n" );
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document.write( "It means that the helper needs 7 hours to do the job alone.    ANSWER\r\n" );
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