Multiple choice

Two cities are 800 miles apart. At 3:00 P.M., plane A leaves one city, traveling toward the other city at a speed of 600 miles per hour. At 4:00 the same afternoon, plane B leaves the first city, travelling in the same direction at a rate of 800 miles per hour. Which of the following answers represents the actual result?

  1. Plane A arrives first, by an hour or more.

  2. Plane A arrives first, by less than an hour.

  3. Both the planes arrive at exactly the same time.

  4. Plane A arrives after plane B, by less than an hour.

  5. Plane A arrives after plane B, by an hour or more.
Reveal answer Fill a bubble to check yourself
B Correct answer
AI explanation

Using the formula Time = Distance / Speed, plane A takes 800 / 60 = 4/3 hours, while plane B takes 800 / 80 = 1 hour. Since plane A leaves an hour earlier, it arrives at 4 + 1.33 = 5.33 hours after 3 P.M., whereas plane B arrives at 4 + 1 = 5 hours after 3 P.M. Therefore, plane A arrives roughly 20 minutes before plane B. Plane A arrives first, by less than an hour.

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