A company manufactures cranes. There are three basic types of crane, labelled A, B and C. Each crane is assembled from a subassembly set {a, b, c, d, e, f } as follows:

In turn, the subassemblies are manufactured from basic components {p, q, r, s, t, u, v, w, x, y} as follows:

(a) Give the make-up of the following subassemblies:

(i) a ∪ b, (ii) a ∪ c ∪ f, (iii) d ∪ e

(b) Given that A is made in Newcastle, and B and C are made in Birmingham, what components need to be available on both sites?