document.write( "Question 1186798: Hi
\n" ); document.write( "If speed is increased by 20 percent a person arrives 15 minutes early. What is the initial time taken by the person.
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Algebra.Com's Answer #817781 by ikleyn(52798) $\"\"$ $\"About$

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\n" ); document.write( "If speed is increased by 20 percent, a person arrives 15 minutes $\"highlight%28cross%28early%29%29\"$ earlier.
\n" ); document.write( "What is the $\"highlight%28cross%28initial%29%29\"$ regular time taken by the person.
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document.write( "Let  \"d\"  be the distance, let \"t\" be the regular (= the scheduled) travel time (in minutes), and let \"u\"  be the regular speed. \r\n" );
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document.write( "Then the increased speed is  1.2u, and reduced traveled time is  t-15 minutes.\r\n" );
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document.write( "We have two equations\r\n" );
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document.write( "     = t              (1)\r\n" );
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document.write( "and\r\n" );
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document.write( "     = t - 15    (2)\r\n" );
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document.write( "From equation (2), we have\r\n" );
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document.write( "     = 1.2*(t-15).\r\n" );
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document.write( "In this equation, replace its left side    by  t, based on equation (1).  \r\n" );
document.write( "You will get then simple linear equation for the single unknown t\r\n" );
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document.write( "    t = 1.2*(t-15).\r\n" );
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document.write( "Simplify and find t\r\n" );
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document.write( "    t = 1.2t - 18\r\n" );
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document.write( "    18 = 1.2t - t\r\n" );
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document.write( "    18 = 0.2t\r\n" );
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document.write( "     t =  =  = 90 minutes.\r\n" );
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document.write( "ANSWER.  The regular (=the scheduled) travel time is 90 minutes.\r\n" );
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