Statistics And Probability Question 110

Question: If three vertices of a regular hexagon are chosen at random, then the chance that they form an equilateral triangle is:

Options:

A) $ \frac{1}{3} $

B) $ \frac{1}{5} $

C) $ \frac{1}{10} $

D) $ \frac{1}{2} $

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Answer:

Correct Answer: C

Solution:

  • [c] Three vertices can be selected in $ ^{6}C_3 $ ways. The only equilateral triangles possible are $ A_1A_3A_5 $ and $ A_2A_4A_6 $ $ p=\frac{2}{^{6}C_3}=\frac{2}{20}=\frac{1}{10} $