document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1179660>Question 1179660</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A motorboat traveling with the current went 42 mi in 3.5 h. Traveling against the current, the boat went 18 mi in 3 h. Find the rate of the boat in calm water and 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 #853777 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13296)</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=853777\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "After using the given information to find that the speed with the current is 12 mph and the speed against the current is 6 mph, the other tutors solved the problem with formal algebra by using a pair of equations involving the boat speed and the current speed.<br><BR>\n" );
document.write( "Of course, a formal algebraic solution is possibly what was required.<br><BR>\n" );
document.write( "However, this kind of problem is so common that, if formal algebra is not required, it can be solved informally with very little effort using logical reasoning.<br><BR>\n" );
document.write( "If the current speed added to the boat speed is 12 mph and the current speed subtracted from the boat speed is 6 mph, then logical reasoning says that the boat speed is halfway between 12 mph and 6mph -- i.e., 9 mph -- and the current speed is then the difference between 9 mph and either 6 mph of 12 mph.<br><BR>\n" );
document.write( "ANSWERS:<BR>\n" );
document.write( "boat speed: 9 mph (halfway between 6 mph and 12 mph)<BR>\n" );
document.write( "current speed: 12-9 = 3 mph; or 9-6 = 3 mph<br><BR>\n" );
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