document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=147112>Question 147112</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Alan and Dave leave from the same point driving in opposite directions, Alan driving at 55 miles per hour and Dave 65 mph. Alan has a one hour head start. How long will they be able to talk on their car phones if the phones have a 250-mile range?  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #107453 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=107453\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Restated, the problem is, when will the sum of their<BR>\n" );
document.write( "distances from the starting point exceed 250 mi?<BR>\n" );
document.write( "Assume I have a stopwatch. I will start the stopwatch <BR>\n" );
document.write( "when Alan has already driven foor 1 hr.<BR>\n" );
document.write( "By then, Alan has driven <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Ba%5D+=+55%2A1 ALIGN=MIDDLE  ALT=\"d%5Ba%5D+=+55%2A1\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Ba%5D+=+55 ALIGN=MIDDLE  ALT=\"d%5Ba%5D+=+55\"   DISABLED_style= \"max-width:90%; height:auto;\" >mi<BR>\n" );
document.write( "I want to find <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Ba%5D+%2B+d%5Bd%5D+=+250 ALIGN=MIDDLE  ALT=\"d%5Ba%5D+%2B+d%5Bd%5D+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "But now, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=d%5Ba%5D ALIGN=MIDDLE  ALT=\"d%5Ba%5D\"   DISABLED_style= \"max-width:90%; height:auto;\" >, Allan's distance from the starting<BR>\n" );
document.write( "point is <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Ba%5D%2At+%2B+55 ALIGN=MIDDLE  ALT=\"r%5Ba%5D%2At+%2B+55\"   DISABLED_style= \"max-width:90%; height:auto;\" > where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t ALIGN=MIDDLE  ALT=\"t\"   DISABLED_style= \"max-width:90%; height:auto;\" > is the time<BR>\n" );
document.write( "showing on my stopwatch.<BR>\n" );
document.write( "Now I can write <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=r%5Ba%5D%2At+%2B+55+%2B+r%5Bd%5D%2At+=+250 ALIGN=MIDDLE  ALT=\"r%5Ba%5D%2At+%2B+55+%2B+r%5Bd%5D%2At+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=55t+%2B+55+%2B+65t+=+250 ALIGN=MIDDLE  ALT=\"55t+%2B+55+%2B+65t+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=120t+=+190 ALIGN=MIDDLE  ALT=\"120t+=+190\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+12%2F19 ALIGN=MIDDLE  ALT=\"t+=+12%2F19\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+.6316 ALIGN=MIDDLE  ALT=\"t+=+.6316\"   DISABLED_style= \"max-width:90%; height:auto;\" >hr<BR>\n" );
document.write( "This is the time after Alan's 1 hr headstart, so they can<BR>\n" );
document.write( "talk on their cellphones for<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=t+=+1.6316 ALIGN=MIDDLE  ALT=\"t+=+1.6316\"   DISABLED_style= \"max-width:90%; height:auto;\" > hr<BR>\n" );
document.write( "t = 1 hr 37.895 min<BR>\n" );
document.write( "t = 1 hr 37 min 54 sec answer<BR>\n" );
document.write( "That's it, unless I goofed.<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=55t+%2B+55+%2B+65t+=+250 ALIGN=MIDDLE  ALT=\"55t+%2B+55+%2B+65t+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=55%2A1.632+%2B+55+%2B+65%2A1.632+=+250 ALIGN=MIDDLE  ALT=\"55%2A1.632+%2B+55+%2B+65%2A1.632+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=89.76+%2B+55+%2B+106.08+=+250 ALIGN=MIDDLE  ALT=\"89.76+%2B+55+%2B+106.08+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=250.84+=+250 ALIGN=MIDDLE  ALT=\"250.84+=+250\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "pretty close </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );