ExamBro
ExamBro
TS EAMCET · Maths · Permutation Combination

\(T_m\) denotes the number of triangles that can be formed with the vertices of a regular polygon of \(m\) sides. If \(T_{m+1}-T_m=15\), then \(m\) is equal to

  1. A 3
  2. B 6
  3. C 9
  4. D 12
Verified Solution

Answer & Solution

Correct Answer

(B) 6

Step-by-step Solution

Detailed explanation

\(T_{m+1}-T_m=15\) \([\because\) triangle can be formed by selecting 3 vertices] \[ \Rightarrow{ }^{m+1} C_3-{ }^m C_3=15 \] On verifying from the options, we get \(m=6\)