document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1189536>Question 1189536</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat travels 343 kilometers in 7 hours going upstream and 819 kilometers in 9 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?  </SPAN>\n" );
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document.write( "b = speed of the boat in still water<BR>\n" );
document.write( "c = speed of the current\r<BR>\n" );
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document.write( "When the boat goes upstream, the current slows the boat down to a speed of b-c\r<BR>\n" );
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document.write( "For the upstream data, we'll plug in the given distance and time to solve for b<BR>\n" );
document.write( "distance = rate*time<BR>\n" );
document.write( "343 = (b-c)*7<BR>\n" );
document.write( "343/7 = b-c<BR>\n" );
document.write( "49 = b-c<BR>\n" );
document.write( "49+c = b<BR>\n" );
document.write( "b = 49+c\r<BR>\n" );
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document.write( "When the boat goes downstream, the current speeds up the boat to a speed of b+c\r<BR>\n" );
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document.write( "Plug in the distance and time pertaining to the downstream scenario, along with b = 49+c, to solve for c.\r<BR>\n" );
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document.write( "Distance = rate*time<BR>\n" );
document.write( "819 = (b+c)*9<BR>\n" );
document.write( "819 = (49+c+c)*9<BR>\n" );
document.write( "819 = (49+2c)*9<BR>\n" );
document.write( "819/9 = 49+2c<BR>\n" );
document.write( "91 = 49+2c<BR>\n" );
document.write( "2c+49 = 91<BR>\n" );
document.write( "2c = 91-49<BR>\n" );
document.write( "2c = 42<BR>\n" );
document.write( "c = 42/2<BR>\n" );
document.write( "c = 21<BR>\n" );
document.write( "<font color=red>The speed of the current is 21 km per hour.</font><BR>\n" );
document.write( "b = 49+c<BR>\n" );
document.write( "b = 49+21<BR>\n" );
document.write( "b = 70<BR>\n" );
document.write( "<font color=red>The boat's speed in still water is 70 km per hour.</font><BR>\n" );
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