document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=69588>Question 69588</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Give a number that is a counter example to conjecture below. Explain your answer choice.\r<BR>\n" );
document.write( "\n" );
document.write( "All numbers that end in the digit 3 are prime. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #49566 by </B><A HREF=/tutors/aboutme.mpl?userid=bucky><B>bucky(2189)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=bucky><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/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=49566\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> The start of the series of numbers that end in 3 are:\r<BR>\n" );
document.write( "\n" );
document.write( "3, 13, 23, 33, 43, 53, 63, 73, 83, 93, 103, ....\r<BR>\n" );
document.write( "\n" );
document.write( "Numbers in this series that are not prime are 33 because it factors into 3 times 11; 63 because its factors include 21*3 and 9*7; and 93 because it can be factored into 31*3.  Because these are just 3 of the counter examples, the premise that all digits that end in the number 3 are prime cannot be true. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );