If for a perfectly competitive firm, price is Rs 7.2, output is 4500 units, average variable costs are Rs 1.2, and average total costs are Rs 4. The firm's profits are equal to
A ceramic pottery unit hires 8 craftsmen by paying each of them Rs 900 per day. The 9th craftsman demands Rs 950 per day. If this craftsman is hired then all other craftsmen must be paid Rs 950. The marginal resource (labour) cost of the 9th craftsman is _________.