document.write( "Question 1058797: In a triathlon, Jenny swim for one hour, bike for 1.75 hours, and ran for one hour. Her average biking speed was two times her average running speed, and her average running speed with eight times her average swimming speed. The total distance of the triathlon was 55.5 km. Calculate Jenny's average swiming speed in kilometers per hour. \n" ); document.write( "

Algebra.Com's Answer #673930 by ikleyn(52847) $\"\"$ $\"About$

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\n" ); document.write( " In a triathlon, Jenny swim for one hour, bike for 1.75 hours, and ran for one hour. Her average biking speed was two times
\n" ); document.write( "her average running speed, and her average running speed $\"highlight%28cross%28with%29%29\"$ was eight times her average swimming speed.
\n" ); document.write( "The total distance of the triathlon was 55.5 km. Calculate Jenny's average swiming speed in kilometers per hour.
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document.write( "Let \"r\" be Jenny's swimming speed, in .\r\n" );
document.write( "Then her running speed was 8r, \r\n" );
document.write( "and her biking speed was 2*(8r) = 16r.\r\n" );
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document.write( "Swimming for 1    hour, Jenny covered the distance of 1*r = r kilometers.\r\n" );
document.write( "Biking   for 1.75 hour, Jenny covered the distance of 1.75*16r = 28r kilometers.\r\n" );
document.write( "Running  for 1    hour, Jenny covered the distance of 1*2r = 8r kilometers.\r\n" );
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document.write( "The total distance Jenny covered was r + 28r + 8r = 37r.\r\n" );
document.write( "It gives you an equation\r\n" );
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document.write( "37r = 55.5 kilometers.\r\n" );
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document.write( "Then r =  = 1.5 km/h.\r\n" );
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document.write( "It was Jemmy's swimming speed.\r\n" );
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document.write( "Answer.  Jemmy's swimming speed was 1.5 km/h.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Lessons to learn from this solution:\r
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document.write( "1.  Think twice or even trice on how to choose the major/leading unknown.\r\n" );
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document.write( "2.  Express other data via this unknown.\r\n" );
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document.write( "3.  Think how to construct (to make) an equation.\r\n" );
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document.write( "4.  If you can do all this steps without making tables, do it without making tables.\r\n" );
document.write( "    It is a preferable way.\r\n" );
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document.write( "5.  Remember, that when solving word problems, your major goal is to make an equation.\r\n" );
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document.write( "    You will become an expert in solving word problems when (and only when) you will learn on how to write the governing equation \r\n" );
document.write( "    instantly after you read and understand the condition.\r\n" );
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