COMEDK · Maths · 4. Permutation Combination
The number of triangles which can be formed by using the vertices of a regular polygon of \((n+3)\) sides is 220 . Then, \(n\) is equal to
- A 8
- B 9
- C 10
- D 11
Answer & Solution
Correct Answer
(B) 9
Step-by-step Solution
Detailed explanation
A polygon with \((n+3)\) sides has \((n+3)\) vertices. A triangle is formed by selecting any \(3\) vertices out of the total vertices. The number of ways to select \(3\) vertices from \((n+3)\) vertices is given by the combination formula \(^{n+3}C_{3}\). Given that the number…
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