document.write( "Question 376030: Clark has a boat that can travel at 15 kph in still water. It can go 140km with the current at the same time it takes to travel 35 km against the current. What is the speed of the river? (Show the complete solution involving Rational Equation) \n" ); document.write( "
Algebra.Com's Answer #267437 by mananth(16946)\"\" \"About 
You can put this solution on YOUR website!
let speed of current be x kph
\n" ); document.write( "speed in still water = 15 kph
\n" ); document.write( "..
\n" ); document.write( "speed upstream = 15-x
\n" ); document.write( "speed downstream = 15+x
\n" ); document.write( "..
\n" ); document.write( "distance upstream = 35 km
\n" ); document.write( "distance downstream = 140 km.
\n" ); document.write( "..
\n" ); document.write( "time upstream = time downstream
\n" ); document.write( "..
\n" ); document.write( "t = d/r
\n" ); document.write( "35/(15-x) = 140/( 15+x)
\n" ); document.write( "cross multiply
\n" ); document.write( "35(15+x) =140(15-x)
\n" ); document.write( "525+35x=2100-140x
\n" ); document.write( "35x+140x=2100-525
\n" ); document.write( "175x=1575
\n" ); document.write( "/175
\n" ); document.write( "x= 1575/175
\n" ); document.write( "x = 9kmh ... speed of current
\n" ); document.write( "...
\n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( "
\n" );