PYQ Vault
EbooksTutor

Crossing a river: time, drift or width

This type of question, asked 3 times: 31 Jan 2023, 2 Apr 2025, 21 Jan 2026 S2. All 3 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    31 Jan 2023

    26
    The speed of a swimmer is 4 km h−14\text{ }km{\text{ }h}^{- 1} in still water. If the swimmer makes his strokes normal to the flow of river of width 1 km1\text{ }km, he reaches a point 750 m750\text{ }m down the stream on the opposite bank. The speed of the river water is___ kmh−1kmh^{- 1}.

  2. Question 2

    2 Apr 2025

    6
    A river is flowing from west to east direction with speed of 9 km h−19\text{ }km{\text{ }h}^{- 1}. If a boat capable of moving at a maximum speed of 27 km h−127\text{ }km{\text{ }h}^{- 1} in still water, crosses the river in half a minute, while moving with maximum speed at an angle of 150∘150^{\circ} to direction of river flow, then the width of the river is :

    Tap an option to check your answer.

  3. Question 3

    21 Jan 2026 S2

    14
    A river of width 200 m is flowing from west to east with a speed of 18 km/h18\text{ }km/h. A boat, moving with speed of 36 km/h36\text{ }km/h in still water, is made to travel one-round trip (bank to bank of the river). Minimum time taken by the boat for this journey and also the displacement along the river bank are ____\_\_\_\_ and ____\_\_\_\_ respectively.

    Tap an option to check your answer.