document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=324913>Question 324913</A>: <I><SPAN STYLE=\"word-break: break-all;\"> If n is a positive integer, which of the following cannot be the units digit of 7^n ?\r<BR>\n" );
document.write( "\n" );
document.write( "(A)1 (B) 3 (C) 5 (D) 7 (E) 9\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #232632 by </B><A HREF=/tutors/aboutme.mpl?userid=JBarnum><B>JBarnum(2146)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=JBarnum><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=JBarnum><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=232632\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 5 cannot ever be in the units digit<BR>\n" );
document.write( "all u have to do is use calculator<BR>\n" );
document.write( "7^1=7<BR>\n" );
document.write( "7^2=.9<BR>\n" );
document.write( "7^3=..3<BR>\n" );
document.write( "7^4=...1<BR>\n" );
document.write( "7^5=....7<BR>\n" );
document.write( "7^6=.....9<BR>\n" );
document.write( "7^7=.....3<BR>\n" );
document.write( "7^8=......1<BR>\n" );
document.write( "7^9=.......7<BR>\n" );
document.write( "7^10=........9<BR>\n" );
document.write( "all the possitive numbers beyond will conclude to ending in only 1,3,7,9<BR>\n" );
document.write( "you can see the pattern 7931 7931 79... </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );