document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1138430>Question 1138430</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat travels 70mi in 2 hours going upstream. It travels 90mi going downstream in the same amount of time. 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 #756263 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13208)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=greenestamps><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=greenestamps><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=756263\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "After determining that the upstream rate is 35mph and the downstream rate is 45mph, finish the problem quickly and easily with logical reasoning.<br><BR>\n" );
document.write( "One of those rates is the speed of the boat in still water PLUS the speed of the current; the other is the speed of the boat in still water MINUS the speed of the current.  Logical reasoning says the speed of the boat in still water has to be the rate halfway between those two rates.<br><BR>\n" );
document.write( "So the speed of the boat in still water is (35+45)/2 = 40mph, which makes the speed of the current 5mph. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );