on her way home from the school board meeting, kelly fills up her car. she likes the idea of using gasoline with ethanol, but thinks her car can only handle 50% ethanol. at the gas station, she can use regular gas with 15% ethanol or e78 fuel with 78% ethanol. how many gallons of each type of fuel should kelly use if she wants to fill up her car with 9 gallons of fuel containing 50% ethanol? 5 gallons of regular gas with 15% ethanol; 4 gallons of e78 fuel with 78% ethanol 6 gallons of regular gas with 15% ethanol; 3 gallons of e78 fuel with 78% ethanol 4 gallons of regular gas with 15% ethanol; 5 gallons of e78 fuel with 78% ethanol 3 gallons of regular gas with 15% ethanol;