Let `T_n` denote the number of triangles, which can be formed using the vertices of a regular polygon of `n` sides. It `T_(n+1)-T_n=21` ,then `n` equals a.`5` b. `7` c. `6` d. `4`

Let T_n denote the number of triangles which can be be formed using the vertices of a regular polygon of n sides. If T_(n+1) - T _n = 21, " then " n =

Let T_n be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If T_(n+1)-T_n=""10 , then the value of n is (1) 5 (2) 10 (3) 8 (4) 7

Let T_n be the number of all possible triangles formed by joining vertices of an n-sided regular polygon. If T_(n+1)-T_n=""10 , then the value of n is (1) 5 (2) 10 (3) 8 (4) 7

The number of triangles that can be formed form a regular polygon of 2n + 1 sides such that the centre of the polygon lies inside the triangle is

The number of triangles that can be formed with 10 points as vertices n of them being collinear, is 110. Then n is a. 3 b. 4 c. 5 d. 6

Consider a polygon of sides 'n' which satisfies the equation 3*^(n)P_(4)=^(n-1)P_(5) . Q. Number of quadrilaterals thatn can be formed using the vertices of a polygon of sides 'n' if exactly 1 side of the quadrilateral in common with side of the n-gon, is

Consider a polygon of sides 'n' which satisfies the equation 3*.^(n)P_(4)=.^(n-1)P_(5) . Q. Number of quadrilaterals that can be made using the vertices of the polygon of sides 'n' if exactly two adjacent sides of the quadrilateral are common to the sides of the n-gon is

The difference between the exterior angles of two regular polygons, having the sides equal to (n-1) and (n+1) is 9^@. Find the value of n.

Let T_r denote the rth term of a G.P. for r=1,2,3, If for some positive integers ma n d n , we have T_m=1//n^2 and T_n=1//m^2 , then find the value of T_(m+n//2.)

If in a series t_n=n/((n+1)!) then sum_(n=1)^20 t_n is equal to :