document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=751345>Question 751345</A>: <I><SPAN STYLE=\"word-break: break-all;\"> There are 5 airplanes ready to depart. Runway A and runway D are available. How many ways can 2 planes be assigned to runways without using the same runway? <BR>\n" );
document.write( "Could you please tell me the answer, and teach me which is N and which is R from the permutation formula, it is a permutation right? Thank you so much for taking the time to answer my question.  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #457131 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><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=457131\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> There are 5 airplanes ready to depart. Runway A and runway D are available. How many ways can 2 planes be assigned to runways without using the same runway? <BR>\n" );
document.write( "Could you please tell me the answer, and teach me which is N and which is R from the permutation formula, it is a permutation right? Thank you so much for taking the time to answer my question.<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Pick a runway: 2 ways<BR>\n" );
document.write( "# of ways to assign 3 planes to that runway: 5C3 = 5C2 = 10 ways<BR>\n" );
document.write( "Note: Every assignment of 3 to that runway assigns 2 planes to the other.<BR>\n" );
document.write( "----<BR>\n" );
document.write( "Each group of 3 planes can be arranged in 3P3 = 3! = 6 ways<BR>\n" );
document.write( "Each group of 2 planes can be arranged in 2P2 = 2! = 2 ways<BR>\n" );
document.write( "------<BR>\n" );
document.write( "Total # of arrangements: 2*10*6*2 = 240 ways<BR>\n" );
document.write( "===========<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.<BR>\n" );
document.write( " </SPAN>\n" );
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