document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=205795>Question 205795</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 2. how many different 4 letter radio station call letters can be made if repeats are allowed and the first letter must be k<BR>\n" );
document.write( "a.1000<BR>\n" );
document.write( "b.17,576<BR>\n" );
document.write( "c.78<BR>\n" );
document.write( "d.456,976 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #155418 by </B><A HREF=/tutors/aboutme.mpl?userid=Targetweek><B>Targetweek(62)</B></A><img src=\"/images/stars/stars-08.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Targetweek><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=155418\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Well to find possible number of permutations (where order does matter), use the equation...<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=n%5Er ALIGN=MIDDLE  ALT=\"n%5Er\"   DISABLED_style= \"max-width:90%; height:auto;\" > Where n is the number of choices (26 in this case) and r is the number chosen at a time (4 in this case)<BR>\n" );
document.write( "When plugged in you get 456,976 different call letters<BR>\n" );
document.write( "divide that number by 26 and you get 17,576<BR>\n" );
document.write( "so the answer is b<BR>\n" );
document.write( "This works because...<BR>\n" );
document.write( "Ex. A,B,C can be arranged...<BR>\n" );
document.write( "A B C<BR>\n" );
document.write( "A C B<BR>\n" );
document.write( "B A C<BR>\n" );
document.write( "B C A<BR>\n" );
document.write( "C A B<BR>\n" );
document.write( "C B A<BR>\n" );
document.write( "there were three choices (or n = 3) and 1/3 of the choices start with A for example, the same applies to the above problem<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );