document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=146038>Question 146038</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Use either the fundamental counting principle or the permutation formulas (or both) to answer the following:\r<BR>\n" );
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document.write( "How many seven-digit phone numbers can be formed if the first digit cannot be 0 and \r<BR>\n" );
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document.write( "a.) repetition of digits is not permitted?\r<BR>\n" );
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document.write( "b.) if repetition of digits is permitted?\r<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 #106673 by </B><A HREF=/tutors/aboutme.mpl?userid=oscargut><B>oscargut(2103)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=oscargut><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=oscargut><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=106673\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How many seven-digit phone numbers can be formed if the first digit cannot be 0 and \r<BR>\n" );
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document.write( "a.) repetition of digits is not permitted?\r<BR>\n" );
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document.write( "9*9*8*7*6*5*4=9*(9!/3!)\r<BR>\n" );
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document.write( "b.) if repetition of digits is permitted?\r<BR>\n" );
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document.write( "9*10*10*10*10*10*10=9*10^6\r<BR>\n" );
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