An electric fan rated at 75 W operates for 5 h each day. If the electricity cost is Rs 10 per kWh, what is the total cost of running the fan for 30 days?

Step-by-step solution

1. Find energy used per day: $E=P\times t=75,\text{W}\times 5,\text{h}=375,\text{Wh}$.
2. Convert to kWh: $375,\text{Wh}=0.375,\text{kWh}$.
3. Multiply by 30 days: $0.375\times 30=11.25,\text{kWh}$.
4. Compute cost: $11.25\times 10=112.5$ Rs.
5. Thus the monthly bill is Rs 112.5.

Concept tested: Energy Consumption

Published 7 October 2026 · How this solution was prepared and checked