Question

In a certain city, electricity costs $0.15 per kwh. what is the annual cost for electricity to power a lamp post for 6.5 hours per day with a 100 watt incandescent light bulb

Answer 1

`power consumption in 1 day=100* 6.5*365\\</p><p>=237250watt hour\\</p><p>1 watt hour=0.001kw hour\\</p><p>so,237250kw hour=237.25\\</p><p>1watt hour=\$ 0.15\\</p><p>so,237.250kw hour=237.25* 0.15</p><p>=\$ 35.58`