Do managers seek to maximise company prots? Explain (25 marks) (b) Explain how a perfectly competitive industry returns to equilibrium when rms are making above-normal (excess) profits. (5 marks) (0) What is the value of the Lerner index for a perfectly competitive industry? (5 marks) (d) Explain why consumer surplus is maximised in a perfectly competitive industry. (5 marks) (e) What happens to consumer surplus when an industry becomes monopolised