Answer:
12 gallons/hour or 1 gallon/5 minutes (1/12 gallon)
Explanation:
assuming gravity can capilary action can be ignored amd has nothing to do with it, 20 minutes is 4 gallons of water gone, so 5 minutes for 1 gallon of water gone. 60 minutes in an hour, so 12 gallons per 60 minutes