7. O, P, Q and R are four points such that OP = p, OQ = q and OR = 3q – 2p.
(i) Find, in terms of p and q,
(ii) Justifying your answer, what can be said about the positions of the points P, Q and R?
(iii) Given that OP = i + 3j and that OQ = 2i + j, find the unit vector in the direction OR.