Question

A housewife uses a 100w bulb for 8h aday and an electric heater of 300w for 4 h a day the total cost for the month of june at the rate of 0.50 rupee per unit will be:

Answer 1

Bulb: 100W x 8h = 800Wh or 0.8kWh
Heater: 300W x 4h = 1.2 kWh

Adding the both the total will be 2.0kWh per day of operation.
Since this is for month of june,so we have 30 days.
Now multiply by 30 days,
30 x 2 kWh= 60kWh

Each unit of electricity (presumably 1 “unit” is 1kWh) costs 0.5 rupees, so the cost for 30 days will be
60kWh x 0.5 rupees/kWh = 30 rupees.