In a n sided polygon joining by straight line all the angular points. . and obtained, the triangles are in number 5n' Find the value of n.

The variance of first n natural numbers is 44. Find the value of n.

If the variance of lst.n even natural numbers is 65, find the value of n

If ^ n P_5 = 20 ^nP_3 find the value of n

The straight line joining the points (-3,-4) and(2,5) is -

Straight lines are drawn by joining m points on a straight line of n points on another line. Then excluding the given points, the number of point of intersections of the lines drawn is (no tow lines drawn are parallel and no these lines are concurrent). a. 4m n(m-1)(n-1) b. 1/2m n(m-1)(n-1) c. 1/2m^2n^2 d. 1/4m^2n^2

There are 15 points in a plane of which 4 points lie in one stright line and another 5 points lie in another straight line . The two lines are parallel and no three of the remaining 6 points are collinear . Find (a) the number of straight lines and (b) the number of trangles that can be formed by joining the 15 points .

The mid value of first (2n + 1 ) consecutive natural number is n + 103/3 Find the value of n.

n points are in space ,no three of which are collinear .if the number of straight lines and triangles , with the given points oniy as the vertices ,obtainted by joining them are equal ,find the value of n .

The straight line joining the points (3,-5 ) and (-3,-5) is parallel to the -

How many different triangles can be formed by joining the angular points of a polygon of n side ?find also the number of diagonals of the polygon .