Multiple choice

Vishnu travelled equal distances at speeds of 10 km/hr, 30 km/hr and 8 km/hr, respectively and took a total of 15.5 minutes to complete. Find the total distance he travelled (in km).

  1. 1

  2. 3

  3. 4

  4. 2

  5. na
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let distance be D for each leg. Total time = D/10 + D/30 + D/8 = 15.5/60 hours. (12D + 4D + 15D) / 120 = 15.5/60. 31D / 120 = 15.5 / 60. 31D = 31. D = 1. Total distance = 3D = 3 km.

AI explanation

Using the formula time equals distance divided by speed, the total time of 15.5 minutes is converted to hours as 31/120 hours. If D is the total distance, each equal part is D/3, so the equation becomes (D/30) + (D/90) + (D/24) = 31/120. Solving the left side gives (3D + D + 5D) / 360, which simplifies to 3D/90 = 31/120, meaning D/30 = 31/120, so the total distance is 3 km.

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