document.write( "Question 1183833: Hi
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Algebra.Com's Answer #814320 by ikleyn(52776) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "When half of the distance is covered with the average speed \"u\",  \r\n" );
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document.write( "and the other half of the distance is covered with the average speed \"v\",\r\n" );
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document.write( "then the average speed covering the total distance is \r\n" );
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document.write( "    w = .      (1)\r\n" );
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document.write( "In your case,  u = 5 km/h;  v = 7.5 km/h;  hence, the average speed covering the total distance is  \r\n" );
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document.write( "    w =  =  = 6 kilometers per hour.     ANSWER\r\n" );
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document.write( "So, to solve the problem, you can start from the first principles and derive the formula, as other tutors \r\n" );
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document.write( "did it in their posts.   It is how the beginner students do.\r\n" );
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document.write( "The other way is to apply this ready to use formula (1)  and answer the question quickly.\r\n" );
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document.write( "Good student should know both methods.\r\n" );
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\n" ); document.write( "\n" ); document.write( "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
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