document.write( "Question 1197385: An ant moves on the following lattice, beginning at the dot labeled $A$. Each minute he moves to one of the dots neighboring the dot he was at, choosing from among its neighbors at random. What is the probability that after $5$ minutes he is at the dot labeled $B$? Image is attached below. \n" ); document.write( "
Algebra.Com's Answer #830631 by greenestamps(13198)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "The analysis by tutor @ikleyn to find the number of ways to end at B is good. But her answer to the question is flawed, because there are not always 4 choices of a direction to go from a given vertex; the total number of possible paths of length 5 starting from point A on the lattice is far less than 4^5. \n" ); document.write( "In the end, I believe the problem has a very simple solution and answer. \n" ); document.write( "In 5 moves on the given lattice, the only points where the ant can end up are the four points 1 unit away from A. Point B is one of those four points; and the symmetry of the lattice means there is equal probability of ending up at any one of those four points. \n" ); document.write( "So the probability of ending at B after 5 moves is 1/4. \n" ); document.write( "ANSWER: 1/4 \n" ); document.write( "--------------------------------------------------------------- \n" ); document.write( "Response to tutor @ikleyn.... \n" ); document.write( "What an absurd note from you regarding my response to the question! \n" ); document.write( "Did you take any time to read my response? or were you just reacting to the idea that anyone would dare to disagree with you? \n" ); document.write( "I will not agree with you when you are WRONG! \n" ); document.write( "The path EEEEE, starting from point A on the lattice, is not possible -- it goes off the lattice. In fact, it is obvious (to anyone who is paying attention to the problem) that a path EEEEE is not possible from ANY point on the lattice. \n" ); document.write( "In your effort to show your superiority (?) in all things mathematical, you might try paying attention to the problem that you are working on. \n" ); document.write( " \n" ); document.write( " |