1. **Stating the problem:** The retailer buys a radio for rs. 225 and has overhead expenses of rs. 15. He sells the radio for rs. 300. We need to determine his profit. 2. **Calculate total cost price:** The total cost price is the sum of the buying price and the overhead expenses. $$\text{Total Cost Price} = 225 + 15 = 240$$ 3. **Calculate profit:** Profit is the difference between the selling price and the total cost price. $$\text{Profit} = 300 - 240 = 60$$ 4. **Conclusion:** The retailer's profit is rs. 60.