Q89 / 160 · WBJEE 2011 · Mathematics

The number of diagonals in a polygon is 20 . The number of sides of the polygon is

  • A
    5
  • B
    6
  • Correct answer
    C
    8
  • D
    10

Solution

Hints: \({ }^{\mathrm{n}} \mathrm{C}_2-\mathrm{n}=20\) \(\mathrm{n}=8\)

Hence, the correct answer is option: 'C'.

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