document.write( "Question 1113363: A boat takes 1 hour to travel 12 miles down river (with the current). Against the same current, it takes 1.25 hours to return up river. If x is the speed of the boat, and y is the speed of the current, find the speed of the boat and the speed of the river \n" ); document.write( "

Algebra.Com's Answer #728392 by ikleyn(52803) $\"\"$ $\"About$

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document.write( "The \"speed equation traveling downstream\" is\r\n" );
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document.write( " = x + y      (12 miles divided by 1 hour = the speed traveling downstream = x + y)\r\n" );
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document.write( "The \"speed equation traveling upstream\" is\r\n" );
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document.write( " = x - y      (12 miles divided by 1.25 hour = the speed traveling upstream = x - y)\r\n" );
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document.write( "Rewrite it as the system\r\n" );
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document.write( "x + y = 12     (1)\r\n" );
document.write( "x - y =  9.6   (2)\r\n" );
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document.write( "Add equations (1) and (2). You will get\r\n" );
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document.write( "2x = 12 + 9.6 = 21.6  ====>  x =  = 10.8.\r\n" );
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document.write( "Then from (1),  y = 12 - 10.8 = 1.2.\r\n" );
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document.write( "Answer.  x = 10.8 mph;  y = 1.2 mph.\r\n" );
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "It is a typical and standard Upstream and Downstream round trip word problem.\r
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\n" ); document.write( "\n" ); document.write( "You can find many similar fully solved problems on upstream and downstream round trips with detailed solutions in lessons \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems \r
\n" ); document.write( "\n" ); document.write( "    - More problems on upstream and downstream round trips \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems solvable by quadratic equations \r
\n" ); document.write( "\n" ); document.write( "    - Unpowered raft floating downstream along a river\r
\n" ); document.write( "\n" ); document.write( "    - Selected problems from the archive on the boat floating Upstream and Downstream \r
\n" ); document.write( "\n" ); document.write( "in this site.\r
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\n" ); document.write( "\n" ); document.write( "Read them attentively and learn how to solve this type of problems once and for all.\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( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
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