(a) Explain the term opportunity cost.
(b) Highlight the relevance of the opportunity cost concept to individuals, firms and government. 

Describe any five problems of distribution in Nigeria. 
 

(a) Define population census.
(b) State the implications of
(i) optimum population.
(ii) over- population. 
 

With the aid of a diagram, explain the super-normal profit of a monopolist. 
 

 What is money? Why do people prefer to hold money?