a)If you owned a business and labour is the only variable input, use a numerical example to illustrate and explain the concept of the marginal product of labour. In your answer, explain when will a change in the marginal product of labour lead to an increase in marginal cost.

b)Use graph (s), illustrate and explain how a change in the marginal cost will affect the average total cost.In your answer, explain at which stage of this relationship will profit start to decline.