http://wtf.blogharbor.com/blog Scientific and mathematical theories, problems and solutions. Includes daily updates of calculus, physics, chemistry, geometry, algebra, and more. en-us Mon, 23 Nov 2009 09:46:13 -0500 Combinatorial Analysis Blogware Crazy Horse http://wtf.blogharbor.com/blog/_archives/2005/9/9/1214378.html http://wtf.blogharbor.com/blog/_archives/2005/9/9/1214378.html Fri, 09 Sep 2005 21:58:43 -0400 <p> A box contains 10 light bulbs. Find the number of <em>n</em> of ordered samples of (a) size 5 with replacement, and (b) size 5 without replacement. </p> Combinatorial Analysis Crazy Horse http://wtf.blogharbor.com/blog/_archives/2005/9/2/1192988.html http://wtf.blogharbor.com/blog/_archives/2005/9/2/1192988.html Fri, 02 Sep 2005 17:10:45 -0400 <p> How many positive integers can be formed from the digits 1, 2, 3, and 4 if no digit is repeated in any one integer? </p> Combinatorial Analysis Crazy Horse http://wtf.blogharbor.com/blog/_archives/2005/8/8/1101339.html http://wtf.blogharbor.com/blog/_archives/2005/8/8/1101339.html Mon, 08 Aug 2005 07:00:00 -0400 Find the number of <span style="font-style: italic;">n</span> ways that a company consisting of 30 members can elect a president, vice-president, and secretary (assuming that no one person can be elected to more than one position).<br> Combinatorial Analysis Crazy Horse http://wtf.blogharbor.com/blog/_archives/2005/7/7/1005690.html http://wtf.blogharbor.com/blog/_archives/2005/7/7/1005690.html Thu, 07 Jul 2005 15:50:19 -0400 There are four train lines between <i>X</i> and <i>Y</i>; and three train lines between <i>Y</i> and <i>Z</i>. Find the number of ways a person can travel:<br> <br> (1) by train from <i>X</i> to <i>Z</i> by way of <i>Y</i><br> <br> (2) roundtrip by train from <i>X</i> to <i>Z</i> by way of <i>Y</i><br> <br> How many ways can the roundtrip by train be taken from <i>X</i> to <i>Z</i> by way of <i>Y</i>, given that you do not use the same train line more than once? Combinatorial Analysis