1. The agent earns a 12% commission on sales up to Rs. 25,000 and a 15% commission on any sales exceeding Rs. 25,000.
2. The agent's total sales for the month were Rs. 67,000.
3. To calculate the commission: the commission on the first Rs. 25,000 of sales is 12% of Rs. 25,000; the commission on sales exceeding Rs. 25,000 is 15% of Rs. 67,000 - Rs. 25,000.