MathDB
Probability of an Arrangement of X's and O's

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January 11, 2009
probabilitycountingdistinguishability

Problem Statement

Thee tiles are marked X X and two other tiles are marked O O. The five tiles are randomly arranged in a row. What is the probability that the arrangement reads XOXOX XOXOX? <spanclass=′latex−bold′>(A)</span> 112<spanclass=′latex−bold′>(B)</span> 110<spanclass=′latex−bold′>(C)</span> 16<spanclass=′latex−bold′>(D)</span> 14<spanclass=′latex−bold′>(E)</span> 13 <span class='latex-bold'>(A)</span>\ \frac{1}{12}\qquad <span class='latex-bold'>(B)</span>\ \frac{1}{10}\qquad <span class='latex-bold'>(C)</span>\ \frac{1}{6}\qquad <span class='latex-bold'>(D)</span>\ \frac{1}{4}\qquad <span class='latex-bold'>(E)</span>\ \frac{1}{3}
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