Q.

Assertion (A): If the points A(6, 1), B(8, 2), C(9, 4) and D(p, 3) are the vertices of a parallelogram (in order), then p = 7.

Reason (R): Diagonals of a parallelogram bisect each other, therefore midpoint of AC = midpoint of BD.

1 Both A and R are true, and R is the correct explanation of A.
 
2 Both A and R are true, but R is not the correct explanation of A  
3 A is true, but R is false.  
4 A is false, but R is true  

Ans.

(1)

Given ABCD is a parallelogra, Diagonals bisect each other, so

Midpoint of AC=Midpoint of BD(6+92,1+42)=(p+82,3+22)Simplifying:(152,52)=(p+82,52)Comparing x-coordinates:152=p+82p+8=15p=7