Question

What will be the cost of using the same for 1 month if one unit of electricity cost rupees 4

Answer 1

If you use x unit of current per day
Then the cost of current per day is:-(4x)
If there are 30 days in this month
then the total cost of curent for this month:-(Cost of curent per day) × (Number of days in this month) = (4x) × (30) = 120x kWh.