document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=288541>Question 288541</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat takes 4 hours to travel 256 mi going upstream. The return trip takes 2 hours going downstream. What is the rate of the boat in still water and what is the rate of the current? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #209140 by </B><A HREF=/tutors/aboutme.mpl?userid=mananth><B>mananth(16946)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mananth><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=mananth><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=209140\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A motorboat takes 4 hours to travel 256 mi going upstream. The return trip takes 2 hours going downstream. What is the rate of the boat in still water and what is the rate of the current?\r<BR>\n" );
document.write( "\n" );
document.write( "let speed of the boat in still water be x\r<BR>\n" );
document.write( "\n" );
document.write( "let the speed of the current be y\r<BR>\n" );
document.write( "\n" );
document.write( "upstream speed of boat is x-y\r<BR>\n" );
document.write( "\n" );
document.write( "distance is 256\r<BR>\n" );
document.write( "\n" );
document.write( "time is 4 hours\r<BR>\n" );
document.write( "\n" );
document.write( "256 / x-y =4\r<BR>\n" );
document.write( "\n" );
document.write( "Down stream\r<BR>\n" );
document.write( "\n" );
document.write( "speed of boat = x+y\r<BR>\n" );
document.write( "\n" );
document.write( "distance = 256\r<BR>\n" );
document.write( "\n" );
document.write( "256/ x+y = 2\r<BR>\n" );
document.write( "\n" );
document.write( "4x-4y=256------------1\r<BR>\n" );
document.write( "\n" );
document.write( "2x+2y=256------------2\r<BR>\n" );
document.write( "\n" );
document.write( "multiply eq 2 by 2\r<BR>\n" );
document.write( "\n" );
document.write( "4x+4y=512-----------3\r<BR>\n" );
document.write( "\n" );
document.write( "Add eq 1 & 3\r<BR>\n" );
document.write( "\n" );
document.write( "4x-4y+4x+4y=512+512\r<BR>\n" );
document.write( "\n" );
document.write( "8x=1024\r<BR>\n" );
document.write( "\n" );
document.write( "x= 1024/8\r<BR>\n" );
document.write( "\n" );
document.write( "=128 mph\r<BR>\n" );
document.write( "\n" );
document.write( "plug the value of x in eq1\r<BR>\n" );
document.write( "\n" );
document.write( "we get y=64mph  speed of the current\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );