document.write( "Question 1183254: Mr. Trump drove to work in the morning at the average speed of 60 miles per hour. He returned home in the evening along the same route and averaged 45 miles per hour. To the nearest tenth, what is his average speed, in miles per hour, for the entire trip? \n" ); document.write( "

Algebra.Com's Answer #813478 by ikleyn(52777) $\"\"$ $\"About$

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\n" ); document.write( "Mr. Trump drove to work in the morning at the average speed of 60 miles per hour.
\n" ); document.write( "He returned home in the evening along the same route and averaged 45 miles per hour.
\n" ); document.write( "To the nearest tenth, what is his average speed, in miles per hour, for the entire trip?
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document.write( "There are two ways to solve the problem.\r\n" );
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document.write( "One way is to apply the ready to use formula for the average speed\r\n" );
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document.write( "     = .     (1)\r\n" );
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document.write( "It gives  \r\n" );
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document.write( "     =  = 51.4  miles per hour  (rounded as requested).     ANSWER\r\n" );
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document.write( "        This way works ideally, if you know this formula (1).\r\n" );
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document.write( "        If you DO NOT know it, you may DEDUCE this formula from the basic notions of Travel & Distance theory.\r\n" );
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document.write( "Let d be one way distance (the same in both directions).\r\n" );
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document.write( "Then the time driving to work is    hours, and\r\n" );
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document.write( "the time driving back is    hours.\r\n" );
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document.write( "The average speed is the total distance, which is 2d, divided by the total time\r\n" );
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document.write( "     =  = cancel d in the numerator and the denominator =  =  = 51.4.\r\n" );
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document.write( "Naturally, you get the same answer.\r\n" );
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\n" ); document.write( "\n" ); document.write( "The problem is just solved, and your horizon became just much wider, if you did not know these methods before.\r
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\n" ); document.write( "\n" ); document.write( "My congratulations, and see the lessons\r
\n" ); document.write( "\n" ); document.write( " - Calculating an average speed: a train going from A to B and back \r
\n" ); document.write( "\n" ); document.write( " - One more problem on calculating an average speed \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Find there many other similar solved problems.\r
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The post-solution note

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\n" ); document.write( "\n" ); document.write( "            All commonly used ways/methods of solving such and similar problems\r
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\n" ); document.write( "\n" ); document.write( "            rotate around the formula (1) - use you it directly or deduce as I showed it in my solution.\r
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\n" ); document.write( "\n" ); document.write( "            Therefore, it is VERY USEFUL to you to know it and to apply appropriately.\r
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