The Langs family drove 225 miles to a beach. Most of their travel was on interstate highways. The Langs drive 65 miles per hour on the last 45 miles of their trip. On average, the Langs traveled 20 miles on one gallon of gas. The gas tank on the Langs' car holds 15 gallons of gas. The Langs had a full tank when their trip began. How many times did they stop to refill the tank before they reach the beach