document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1197136>Question 1197136</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Joseph traveled from Boston to Birmingham at 50 mph and then back to Boston at 40 mph. What was Joseph's average speed on the round trip? </SPAN>\n" );
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document.write( "The distances there and back are the same, and the ratio of the speeds is 50:40 = 5:4.  That means the ratio of times spent at the two speeds was 4:5.<br><BR>\n" );
document.write( "So he spent 4x hours going, at 50mph, traveling 4x(50) = 200x miles; and he spent 5x hours returning, at 40mph, traveling 5x(40) = 200x miles.<br><BR>\n" );
document.write( "The round trip was then 400x miles in 9x hours, making his average speed 400/9 = 44 4/9 mph.<br><BR>\n" );
document.write( "ANSWER: 44 4/9 mph<br><BR>\n" );
document.write( "Or you can work the problem as a weighted average: he spent 4/9 of his time at 50mph and 5/9 of his time at 40mph:<br><BR>\n" );
document.write( "(4/9)(50)+(5/9)(40) = 200/9+200/9 = 400/9 = 44 4/9<br><BR>\n" );
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