The Carey family took a trip in November. Mary is calculating the gas mileage in miles per gallon for her dad's truck. When he fills the tank, her dad records the miles on the truck as 15,345. Her dad pays $53.28 to fill up the empty gas tank of the truck. What is the size of the truck's tank in gallons if it cost $3.33 per gallon? Round your answer to the nearest whole number. Be sure to include the correct units in your final answer. *