Multiple choice

Stefanie embarks on a road trip from Dallas to Austin, Texas, covering 180 miles. She covers the first 70 miles in 2 hours without any stops. After taking a 1-hour lunch break, she resumes her journey and drives the remaining 110 miles at an average speed of 55 miles per hour. What is her average speed for the entire trip, including the lunch break?

  1. 34 miles per hour

  2. 36 miles per hour

  3. 40 miles per hour

  4. 42 miles per hour

  5. 48 miles per hour
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total distance is 180 miles. Total time is 2 hours (first part) + 1 hour (break) + (110 miles / 55 mph) = 2 + 1 + 2 = 5 hours. Average speed = Total distance / Total time = 180 / 5 = 36 mph.

AI explanation

Using the formula time = distance divided by speed, the time taken to drive the remaining 110 miles is 110 divided by 55, equaling 2 hours. Including the 2 hours for the first part and the 1-hour break, the total time for the trip is 5 hours. Therefore, the average speed for the entire trip over 180 miles is 180 divided by 5, which equals 36 miles per hour.

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