document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1183833>Question 1183833</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Hi<BR>\n" );
document.write( "Bob went up a mountain at 5km per hour and down the mountain at 7.5 km per hour. <BR>\n" );
document.write( "What was the average speed up and down the mountain. \r<BR>\n" );
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document.write( "Thanks </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #814317 by </B><A HREF=/tutors/aboutme.mpl?userid=greenestamps><B>greenestamps(13198)</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=814317\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <br><BR>\n" );
document.write( "First solution method:<br><BR>\n" );
document.write( "As shown by the other tutor, using d for the distance each way.<br><BR>\n" );
document.write( "Second solution method -- easier for many students, because no variables are involved.<br><BR>\n" );
document.write( "Choose a \"nice\" number for the distance; then solve in the same way as when using the variable d.  Since the two speeds are 5 and 7.5km/hr, let the distance each way be 15km.  Then<br><BR>\n" );
document.write( "time up the mountain = 15/5 = 3 hours<BR>\n" );
document.write( "time down = 15/7.5 = 2 hours<br><BR>\n" );
document.write( "Total distance 30km; total time 5 hours; average speed = total distance divided by total time = 30/5 = 6km/hr.<br><BR>\n" );
document.write( "Third solution method -- harder to understand; but faster if you understand how to use it.<br><BR>\n" );
document.write( "The ratio of speeds is 5:7.5 = 2:3; since the distances are the same, that means the ratio of times at the two speeds is 3:2.<br><BR>\n" );
document.write( "So 3/5 of the time he is traveling at 5km/hr and 2/5 of the time he is traveling at 7.5km/hr.  That makes the average speed<br><BR>\n" );
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