document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=50670>Question 50670</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A crew can row 8km downstreat and back in 4.8 hours.  If the rate of the current is 4 kph, find the rate of the crew in still water.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Oh please help me!!<BR>\n" );
document.write( "Matt </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #33775 by </B><A HREF=/tutors/aboutme.mpl?userid=venugopalramana><B>venugopalramana(3286)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=venugopalramana><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.geocities.com/venugopalramana/FREE_MATHS_ASSISTANCE.html valign=middle><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=33775\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> A crew can row 8km downstreat and back in 4.8 hours. If the rate of the current is 4 kph, find the rate of the crew in still water. <BR>\n" );
document.write( "let crew's speed in still water =v kph<BR>\n" );
document.write( "water current = 4 kph<BR>\n" );
document.write( "speed up stream = v-4 kph<BR>\n" );
document.write( "speed down stream =v+4 kph<BR>\n" );
document.write( "total time to ride 8 km up and down=8{1/(v-4)+1/(v+4)=16v/(v^2-16)=4.8<BR>\n" );
document.write( "4.8v^2-16*4.8=16v<BR>\n" );
document.write( "0.3 v^2-v-4.8=0<BR>\n" );
document.write( "3v^2-10v-48=0<BR>\n" );
document.write( "3v^2-18v+8v-48=0<BR>\n" );
document.write( "3v(v-6)+8(v-6)=0<BR>\n" );
document.write( "(v-6)(3v+8)=0<BR>\n" );
document.write( "v=6\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );