Multiple choice

During a race, a runner notices a rival athlete ahead. The runner starts at a distance of 0.5 miles from the rival, who is running at a speed of 9 mph. If the runner accelerates to 11 mph, how long will it take to catch up to the rival?

  1. 25 minutes

  2. 23 minutes

  3. 18 minutes

  4. 15 minutes

  5. 9 minutes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Relative speed = 11 - 9 = 2 mph. Distance = 0.5 miles. Time = 0.5 / 2 = 0.25 hours = 15 minutes.

AI explanation

The runner must close a gap of 0.5 miles, and the relative speed is the difference between their speeds: 11 mph - 9 mph = 2 mph. Using the formula time equals distance divided by speed, the time to catch up is 0.5 miles / 2 mph = 0.25 hours. Multiplying by 60 to convert this to minutes gives 0.25 * 60 = 15 minutes.

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