document.write( "Question 1147728: Adam and Natasha row their canoe 12 miles downstream in 2 hours. After a picnic, they row their canoe back upstream. After 3 hours of rowing, they only travel 12 miles. Assuming that Adam and Natasha canoe at a constant rate, and that the river's current is constant, find the speed at which Adam and Natasha can row in still water. \n" ); document.write( "
Algebra.Com's Answer #769104 by ankor@dixie-net.com(22740)\"\" \"About 
You can put this solution on YOUR website!
Adam and Natasha row their canoe 12 miles downstream in 2 hours.
\n" ); document.write( " After a picnic, they row their canoe back upstream.
\n" ); document.write( " After 3 hours of rowing, they only travel 12 miles.
\n" ); document.write( " Assuming that Adam and Natasha canoe at a constant rate, and that the river's current is constant, find the speed at which Adam and Natasha can row in still water.
\n" ); document.write( ":
\n" ); document.write( "let s = their speed in still water
\n" ); document.write( "let c = the rate of the current
\n" ); document.write( "then
\n" ); document.write( "(s+c) = their ground speed downstream
\n" ); document.write( "and
\n" ); document.write( "(s-c) = their ground speed upstream
\n" ); document.write( ":
\n" ); document.write( "Write a distance equation for each way; dist = time * speed
\n" ); document.write( "2(s+c) = 12
\n" ); document.write( "3(s-c) = 12
\n" ); document.write( "simplify both equations, divide the 1st by 2, the 2nd by 3
\n" ); document.write( "s + c = 6
\n" ); document.write( "s - c = 4
\n" ); document.write( "-------------addition eliminates c, find s
\n" ); document.write( "2s + 0 = 10
\n" ); document.write( "s = 10/2
\n" ); document.write( "s = 5 mph their speed in still water
\n" ); document.write( ":
\n" ); document.write( ":
\n" ); document.write( "see if that checks out (current rate is 1 mph)
\n" ); document.write( "2(5+1) = 12
\n" ); document.write( "3(5-1) = 12 \n" ); document.write( "
\n" );