document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=464325>Question 464325</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What is the sum of all the 4-digit numbers all of whose digits are odd?<BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #318081 by </B><A HREF=/tutors/aboutme.mpl?userid=jorel1380><B>jorel1380(3719)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=jorel1380><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=jorel1380><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=318081\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The sum of all numbers between 1 and n can be found using the equation:n(n+1)/2<BR>\n" );
document.write( "So, therefore, the sum of all numbers between 1 and 1000 is <BR>\n" );
document.write( "1000(1001)/2=500500<BR>\n" );
document.write( "Likewise, the sum of all numbers between 1 and 9999 is<BR>\n" );
document.write( "9999(10000)/2=49995000<BR>\n" );
document.write( "Thus, the total of all numbers between 1000 and 9999 is the difference between the  two, or<BR>\n" );
document.write( "49995000-500500=49494500<BR>\n" );
document.write( "The sum of all the odd integers in that span is roughly 1/2 of all the integers so our answer is<BR>\n" );
document.write( "49494500/2=24747250..<BR>\n" );
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