document.write( "Question 1111037: A crew rowed 7 miles upstream in 2 hours and the 6 1/2 miles downstream in 1 hour. Find the rate of the crew in still water and the rate of the current. \n" ); document.write( "
Algebra.Com's Answer #726069 by ikleyn(52781)\"\" \"About 
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document.write( "Let \"u\" be the speed of the boat in still water (in mph)\r\n" );
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document.write( "and \"v\" be the speed of the current.\r\n" );
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document.write( "Then the effective speed upstream is\r\n" );
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document.write( "u - v = 3.5  mph    (1)      (=7/2 mph)\r\n" );
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document.write( "while the effective speed downstream is  \r\n" );
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document.write( "u + v = 6.5  mph    (2)      (from the condition)\r\n" );
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document.write( "Adding (1) and (2), you find  2u = 3.5+6.5 = 10  ====>  u = 5 mph.\r\n" );
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document.write( "Then  from (2),  v = 6.5 - 5 = 1.5 mph.\r\n" );
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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
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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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