m points on one straight line are joined to n points on another straight line. The number of points of intersection of the line segments thus formed is (A) `^mC-2.^nC_2` (B) `(mn(m-1)(n-1))/4` (C) `(^mC_2.^nC_2)/2` (D) `^mC_2+^nC_2`

Assertion: If each of m points on one straight line be joined to each of n points on the other straight line terminated by the points, then number of points of intersection of these lines excluding the points on the given lines is (mn(m-1)(n-1))/2 Reason: Two points on one line and two points on other line gives one such point of intersection. (A) Both A and R are true and R is the correct explanation of A (B) Both A and R are true R is not the correct explanation of A (C) A is true but R is false. (D) A is false but R is true.

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

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

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

"^mC_1=^nC_2 , then -

The coefficient of x^4 in the expansion of (1+x+x^2+x^3)^n is (A) ^nC_4 (B) ^nC_4+^nC_2 (C) ^nC_4+^nC_2+^nC_4.^nC_2 (D) ^nC_4+^nC_2+^nC_1.^nC_2

if the straight line joining the points (3,4) and (2,-1) be parallel to the line joining the points (a,-2) and (4,-a), find the value of a.

If the straight line joining the points (3,4) and (2,-1) be parallel to the line joining the points (a,-2) and (4,-a), find the value of a.

If m parallel lines in a plane are intersected by a family of n parallel lines,the number of parallelograms that can be formed is a.(1)/(4)mn(m-1)(n-1) b.(1)/(4)mn(m-1)(n-1) c.(1)/(4)m^(2)n^(2) d.none of these

Two point charges -2nC and +8nC are separated in air by a distance of 0.10m.Find the position of the neutral point along the line joining the 2 point charges.