document.write( "Question 1125421: I would be so happy if someone can help me work this out please.
\n" ); document.write( "Ina Crespo rowed 12 miles down the Habashabee River in 1.5 hours, but the return trip took her 4 hours. Find the rate Ina rows in still water and the rate of the current. Let x represent the rate Ina can row in still water and let y represent the rate of the current.
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\n" ); document.write( "\n" ); document.write( "Ina can row ____mph in still water. \n" ); document.write( "

Algebra.Com's Answer #741741 by ikleyn(52877) $\"\"$ $\"About$

You can put this solution on YOUR website!

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document.write( "Let x represent the rate Ina can row in still water and \r\n" );
document.write( "let y represent the rate of the current. \r\n" );
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document.write( "Then  her  effective speed downstream  is  x+y   miles per hour,\r\n" );
document.write( "while her  effective speed upstream    is  x-y  miles per hour.\r\n" );
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document.write( "    // It is first major point you need understand and use in this sort of problems.\r\n" );
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document.write( "Now, \"speed\" equation for boat floating downstream is \r\n" );
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document.write( " = u + v    (1)    (speed downstream = the distance divided by time downstream)\r\n" );
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document.write( "Next, \"speed\" equation for boat floating upstream is \r\n" );
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document.write( " = u - v    (2)    (speed upstream = the distance divided by time  duptream)\r\n" );
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document.write( "    // It is the second major point in solving such problems: you must understand and write these equation automatically !\r\n" );
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document.write( "Simplify equations (1) and (2)\r\n" );
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document.write( "u + v =  8     (3)\r\n" );
document.write( "u - v =  3     (4)\r\n" );
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document.write( "Now add equations (3) and (4) to eliminate \"v\". You will get\r\n" );
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document.write( "2u = 8 + 3 = 13  ====>  u =  = 6.5.\r\n" );
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document.write( "Thus you just found the boat' speed in still water. It is 6.5 miles per hour.\r\n" );
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document.write( "Next, you can find the current rate from eq(4)  v = 8 - u = 8 - 6.5 = 1.5 miles per hour.\r\n" );
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document.write( "Answer.  The boat' speed in still water is 6.5 miles per hour.\r\n" );
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document.write( "         The current speed is 1.5 miles per hour.\r\n" );
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document.write( "Solved.  I advise you to make the check on your own.\r\n" );
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document.write( "         After making the check, you will understand the problem and the solution MUCH better.\r\n" );
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\n" ); document.write( "\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, where you will find other similar solved problems with detailed explanations.\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( "\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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