1. **Problem Statement:** Calculate the electricity consumption and bill for Bikash's house in Mangsir month using the 5 Ampere tariff rates. 2. **Given Data:** - Present reading = 1248 - Previous reading = 1198 - Tariff rates for 5 Ampere: - 0-20 units: Service charge = 30, Energy charge = 0 - 21-30 units: Service charge = 50, Energy charge = 6.50 - 31-50 units: Service charge = 50, Energy charge = 8.00 - 51-100 units: Service charge = 75, Energy charge = 9.50 - Note: If consumption > 20 units, Rs. 3 per unit charged for first 20 units. 3. **Step 1: Calculate consumption** $$\text{Consumption} = 1248 - 1198 = 50 \text{ units}$$ 4. **Step 2: Calculate bill amount** Since consumption is 50 units (>20), the tariff applies as: - First 20 units: Rs. 3 per unit - Next 10 units (21-30): Rs. 6.50 per unit - Next 20 units (31-50): Rs. 8.00 per unit - Service charge for 31-50 units = Rs. 50 Calculate energy charge: $$\text{Energy charge} = (20 \times 3) + (10 \times 6.5) + (20 \times 8) = 60 + 65 + 160 = 285$$ Total bill: $$\text{Total} = \text{Service charge} + \text{Energy charge} = 50 + 285 = 335$$ 5. **Step 3: Maximum units for Rs. 175 bill** Let $x$ be the maximum units consumed. If $x \leq 20$, bill = 30 (service) + 0 (energy) = 30 < 175, so check higher units. If $20 < x \leq 30$: $$\text{Bill} = 50 + 6.5(x - 20) + 3 \times 20 = 50 + 6.5(x - 20) + 60 = 110 + 6.5(x - 20)$$ Set bill = 175: $$175 = 110 + 6.5(x - 20)$$ $$65 = 6.5(x - 20)$$ $$x - 20 = \frac{65}{6.5} = 10$$ $$x = 30$$ If $x > 30$, bill will exceed 175, so maximum units = 30. **Final answers:** - i. Consumption = 50 units - ii. Bill amount = 335 - iii. Maximum units for Rs. 175 bill = 30 units