Reasoning : General Mental Ability

Q 4 / 45

UPSC CSE Prelims 2024

A person walks 100 m West ward, then turns left and walks 100 m. He then takes 225° turn clockwise. In which direction is he walking now?

EXPLANATION

Correct Option (4)

North-East

The person's movement can be analyzed in sequential steps:

  • Initially, the person walks 100 m Westward. The current direction of movement is West.
  • Next, the person turns left and walks 100 m. When facing West, a left turn leads to the South direction. Therefore, the person is now walking South.
  • Finally, the person takes a 225° turn clockwise from the current direction (South).
    • A 180° clockwise turn from South would orient the person towards North.
    • The remaining turn required is 225° - 180° = 45°.
    • Turning an additional 45° clockwise from North results in the North-East direction.

Thus, the person is walking in the North-East direction.

Incorrect Options:

  • Option (1) South-West: This direction would be achieved by turning 45° counter-clockwise from South, or a 135° clockwise turn from South, not a 225° clockwise turn.
  • Option (2) South-East: This direction is the initial direction of movement after the first left turn, before the 225° clockwise turn. A 225° clockwise turn from South would pass North and continue towards North-East.
  • Option (3) North-West: This direction would be achieved by turning 225° counter-clockwise from South, or a 135° clockwise turn from South, which is different from the specified 225° clockwise turn.