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COMEDK2024MathematicsProbability

Three vertices are chosen randomly from the 10 vertices of a regular 10 sided polygon. The probability that they form the vertices of an isosceles triangle is

Options

  1. A4 7
  2. B3 7
  3. C4 8
  4. D3 8

Correct answer

D. 3 8

Step-by-step solution

Number of triangle formed = ¹⁰ C₃ Number of isosceles triangle =10 ( 10-1 2 ) =5 9=45 So, required aligned probability & = 45 ¹⁰ C₃ & = 45 3 2 10 9 8 = 3 8 aligned

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