document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=224610>Question 224610</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat travel 30 miles upstream against the current in the same amount of time it take to travel 42 miles downstream with the current. If the rate of  the current is 4MPH, what is the rate of the boat in still water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #167811 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=167811\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> d=rt or t=d/r<BR>\n" );
document.write( "t=30/(r-4)<BR>\n" );
document.write( "t=42/(t+4)<BR>\n" );
document.write( "Since the times are equal then:<BR>\n" );
document.write( "30/(r-4)=42/(r+4)<BR>\n" );
document.write( "42(r-4)=30(r+4)<BR>\n" );
document.write( "42r-168=30r+120<BR>\n" );
document.write( "42r-30r=120+168<BR>\n" );
document.write( "12r=288<BR>\n" );
document.write( "r=288/12<BR>\n" );
document.write( "r=24 mph. is the boat's speed in still water.<BR>\n" );
document.write( "Proof:<BR>\n" );
document.write( "30/(24-4)=42/(24+4)<BR>\n" );
document.write( "30/20=42/28<BR>\n" );
document.write( "1.5=1.5 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );