The following are some costs incurred by a shoe manufacturer. Decide whether each one is a fixed cost or a variable cost or has some element of both.

(a) The cost of leather;

(b) The fee paid to an advertising agency;

(c) Wear and tear on machinery;

(d) Business rates on the factory;

(e) Electricity for heating and lighting;

(f) Electricity for running the machines;

(g) Basic minimum wages agreed with the union;

(h) Overtime pay;

(i) Depreciation of machines as a result purely of their age (irrespective of their condition).