An electric bulb of 60W is lit for 10 hours a day, what is the amount to be paid in a month of 30 days, if one unit of electricity costs Rs. 3.50?

1 kwh = 1000W

Bulb Rating = 60 W =.06kW

Bulb illuminations last for > 10 hours/day

Bulb consumes units( kWH)/day= .06×10= .6kWH/ day = .6 units/ day

In 30 Days =.6×30 =18units

1.50/unit = cost

12 units = 3.50×18 = $63

In one month, the Rs.63/- Therfere must be paid