document.write( "Question 940879: riley can paddle 30 miles downstream in 3 hours. upstream takes one hour more to go 6 miles less. Find the rate of the current. \n" ); document.write( "
Algebra.Com's Answer #573702 by ankor@dixie-net.com(22740)\"\" \"About 
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Riley can paddle 30 miles downstream in 3 hours.
\n" ); document.write( " upstream takes one hour more to go 6 miles less.
\n" ); document.write( " Find the rate of the current.
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\n" ); document.write( "let s = his paddling speed in still water
\n" ); document.write( "let c = the rate of the current
\n" ); document.write( "then
\n" ); document.write( "(s+c) = his effective speed downstream
\n" ); document.write( "and
\n" ); document.write( "(s-c) = his effective speed upstream
\n" ); document.write( ":
\n" ); document.write( "Write a distance equation for each way; dist = time * speed
\n" ); document.write( "3(s+c) = 30
\n" ); document.write( "4(s-c) = 24; (one hr longer and 6 mi less)
\n" ); document.write( ":
\n" ); document.write( "We can simplify both these equations, divide the 1st one by 3, the 2nd one by 4
\n" ); document.write( "s + c = 10
\n" ); document.write( "s - c = 6
\n" ); document.write( "----------Adding eliminates c, find s
\n" ); document.write( "2s = 16
\n" ); document.write( "s = 16/2
\n" ); document.write( "s = 8 mph
\n" ); document.write( "find the current using the equation s + c = 10
\n" ); document.write( "8 + c = 10
\n" ); document.write( "c = 10 - 8
\n" ); document.write( "c = 2 mph is the current
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "you can confirm this by putting these values in the original equations \n" ); document.write( "
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