A boat takes 4 hours for travelling downstream from point A to point B aild…

20232023

A boat takes 4 hours for travelling downstream from point A to point B aild coming back to point A upstream. If the velocity of the stream is 2 kmph and the speed of the boat in still water is 4 kmph, what is the distance between A and B?

  1. A.

    9 km

  2. B.

    3 km

  3. C.

    6 km

  4. D.

    2 km

Attempted by 12 students.

Show answer & explanation

Correct answer: C

Answer: 6 km

Explanation:

  1. Let the distance between A and B be x km.

  2. Boat speed in still water = 4 km/h; stream speed = 2 km/h.

  3. Downstream speed = 4 + 2 = 6 km/h. Upstream speed = 4 - 2 = 2 km/h.

  4. Total time for downstream and upstream is 4 hours, so:

    x/6 + x/2 = 4

  5. Multiply both sides by 6: x + 3x = 24 ⇒ 4x = 24 ⇒ x = 6.

  6. Therefore, the distance between A and B is 6 km.

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