Multiple choice A 100-watt bulb lights 10 hours daily. In a month of 30 days it will consume: 100 KWH units 30 KWH units 3 KWH units 10 KWH units Reveal answer Fill a bubble to check yourself B Correct answer Explanation Energy = Power x Time. 100 watts x 10 hours/day = 1000 watt-hours or 1 KWH per day. For 30 days: 1 KWH/day x 30 days = 30 KWH units total.