The area of the square, one of whose diagonals is $$3\widehat i + 4\widehat j$$, is

ABCD is a parallelogram and P is the point of intersection of the diagonals. If O is the origin, then OA + OB + OC + OD is equal to

If b and c are the position vectors of the points B and C respectively, then the position vector of the point D such that BD = 4 BC is

If the position vector a of the point (5, n) is such that | a | = 13, then the value(s) of n can be