Which of the following is the most appropriate unit to describe the rate at which water flows out through a standard household faucet? . -minutes per gallon, because the independent quantity is volume of water in gallons and dependent quantity is time in minutes.. -gallons per minute, because the independent quantity is volume of water in gallons and dependent quantity is time in minutes.. -minutes per gallon, because the independent quantity is time in minutes and dependent quantity is volume of water in gallons.. -gallons per minute, because the independent quantity is time in minutes