document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=606313>Question 606313</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Jim traveled 240 miles to a convention. Later, his wife Ann drove up to meet him. Ann's average speed exceeded Jim's by 4 mph, and the trip took her 15 minutes less time. Find Ann's speed. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #382022 by </B><A HREF=/tutors/aboutme.mpl?userid=vksarvepalli><B>vksarvepalli(154)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=vksarvepalli><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=vksarvepalli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=382022\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let the average speed of Jim be 'x' mph<BR>\n" );
document.write( "so the average speed of Ann will be 'x+4' mph\r<BR>\n" );
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document.write( "let time taken by Jim to travel is 't' hrs.<BR>\n" );
document.write( "then the time taken by Ann will be 't-0.25' hrs. (Since 15 mins = .25 hrs)\r<BR>\n" );
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document.write( "Now, average speed = total distance travelled / total time taken.\r<BR>\n" );
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document.write( "  so,   x = 240/t    --- eq.1\r<BR>\n" );
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document.write( "        x+4 = 240/(t-0.25)  -----eq.2\r<BR>\n" );
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document.write( "Substituting eq.1 in eq.2\r<BR>\n" );
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document.write( "we get           (240/t) + 4 = 240/(t-0.25)  \r<BR>\n" );
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document.write( "           =>     1/t + 1/60 = 1/(t-0.25)<BR>\n" );
document.write( "           =>     1/(t-0.25) - 1/t = 1/60<BR>\n" );
document.write( "           =>      4t^2-t-60 = 0\r<BR>\n" );
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document.write( "    So t= 4 or t= -15/4\r<BR>\n" );
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document.write( "since time cannot be a negative value.\r<BR>\n" );
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document.write( "   t = 4 hrs.<BR>\n" );
document.write( "from eq.1   x = 240/t = 240/4 = 60 mph\r<BR>\n" );
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document.write( "  So, Ann's speed = x+4 = 60+4 = 64 mph\r<BR>\n" );
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document.write( "Ans: 64 mph </SPAN>\n" );
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