2016 AMC 8

Complete problem set with solutions and individual problem pages

Problem 14 Medium

Karl's car uses a gallon of gas every 35 miles, and his gas tank holds 14 gallons when it is full. One day, Karl started with a full tank of gas, drove 350 miles, bought 8 gallons of gas, and continued driving to his destination. When he arrived, his gas tank was half full. How many miles did Karl drive that day?

  • A.

    525

  • B.

    560

  • C.

    595

  • D.

    665

  • E.

    735

Answer:A

Since he uses a gallon of gas every 35 miles, he had used \frac{350}{35} = 10 gallons after 350 miles. Therefore, after the first leg of his trip he had 14 - 10 = 4 gallons of gas left. Then, he bought 8 gallons of gas, which brought him up to 12 gallons of gas in his gas tank. When he arrived, he had \frac{1}{2} \cdot 14 = 7 gallons of gas. So he used 5 gallons of gas on the second leg of his trip. Therefore, the second part of his trip covered 5 \cdot 35 = 175 miles. Adding this to the 350 miles, we see that he drove 350 + 175 = \boxed{\textbf{(A)} \, 525} miles.