Answer:
1680 kwhr
Explanation:
See attached for explanation. I converted watt*hr to kW*hr by dividing by 1000.
Fans Bulbs
40 100
50 60 W
10 6 hours/day
20000 36000 W*hr/day
30 30 days/month
600000 1080000 W*hr/month
600 1080 kWhr/month
Total = 1680 kWhr/month