John's car gets 30 mpg. He drives 20 miles to work each way 5 days a week. He also drives another 40 miles a week for leisure travel. How many gallons of gas does he use a week? Think carefully first, then make a decision:
He drives 20 * 2 = 40 miles per day for work. So he drives 40 * 5 = 200 miles for work. So he drives a total of 200 + 40 = 240 miles per week. That means he uses 240 / 30 = 8 gallons of gas a week. So, the answer is 8.