document.write( "Question 1059114: A boat moves 7 kilometers upstream
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Algebra.Com's Answer #674220 by ikleyn(52781) $\"\"$ $\"About$

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\n" ); document.write( "A boat moves 7 kilometers upstream in the same amount of time it moves 20 kilometers downstream.
\n" ); document.write( "If the rate of the current is 5 kilometers per hour, find the rate of the boat in still water.
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document.write( "Let \"u\" be the rate of the boat in still water, in .\r\n" );
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document.write( "Then your governing equation (\"time equation\") is\r\n" );
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document.write( " = .\r\n" );
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document.write( "The left side is the time to travel 7 kilometers upstream.\r\n" );
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document.write( "The right side is the time to travel 20 kilometers downstream.\r\n" );
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document.write( "To solve the equation, multiply both sides by (u-5)*(u+5). You will get\r\n" );
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document.write( "7(u+5) = 20(u-5),  or\r\n" );
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document.write( "7u + 35 = 20u - 100,  or\r\n" );
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document.write( "35 + 100 = 20u - 7u,  or\r\n" );
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document.write( "135 = 13u  --->  u = .\r\n" );
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document.write( "Answer. The rate of the boat in still water is   .\r\n" );
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document.write( "        Unfortunately, the person who invented these input numbers, select them too curve to get an integer number as the answer.\r\n" );
document.write( "        Perhaps, this person didn't solve the problem himself.\r\n" );
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\n" ); document.write( "\n" ); document.write( "It is a typical \"upstream and downstream Travel and Distance\" word problem.\r
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\n" ); document.write( "\n" ); document.write( "See the lessons \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems \r
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\n" ); document.write( "\n" ); document.write( "    - Selected problems from the archive on the boat floating Upstream and Downstream \r
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\n" ); document.write( "\n" ); document.write( "You will find the detailed solutions of many similar problems there. \r
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\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lessons are the part of this textbook under the section \"Word problems\", the topic \"Travel and Distance problems\".\r
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\n" ); document.write( "\n" ); document.write( "If after reading my solution you still have a question \"why the governing equation has this form ?\",
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