Manoj walks 40 metres towards North. Then he takes left turn and walks 20 meters. He again takes left turn and walks 40 metres. How far and in which direction is he from the starting point?

Appeared in: RRB Staff Nurse Kolkata-2015

Explanation

The problem requires calculating the final displacement, which is the shortest distance and direction from the starting point to the final point.
Manoj's first move is 40m North, and his third move is 40m South. These two movements are equal and opposite, so they cancel each other out in the vertical (North-South) axis.
The only remaining movement is the 20m walk to the West.
This means his final position is exactly 20 meters to the West of where he started.

Option A: This option incorrectly uses the total distance walked (40 + 20 + 40 = 100m) instead of the displacement. The direction is also incorrect.
Option B: This value seems to be an arbitrary miscalculation. The direction 'East' is the opposite of the correct direction.
Option C: This value might be obtained by incorrectly adding or subtracting distances (e.g., 40 + 20 = 60). While the direction 'West' is correct, the distance is wrong.

Visual 1: Diagram: A simple 2D diagram showing the path of movement on a grid. Start at an origin point, draw an arrow up for North, left for West, and then down for South. This visually demonstrates that the final position is 20 units to the left of the origin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Direction and Distance Reasoning as background academic context rather than a clinical decision trigger.
This is a non-clinical reasoning question.
Logical reasoning skills are essential for nurses for critical thinking and problem-solving in complex clinical situations.
For example, a nurse needs to follow multi-step protocols accurately, which requires the same sequential thinking as solving this problem.

How to Approach the Question

First, identify the starting point and the cardinal directions (North, East, South, West).
Second, trace each movement step-by-step. It is highly recommended to draw a simple diagram.
For each step, note the direction of movement and the distance covered.
Pay close attention to the turns ('left' or 'right'). A left turn from North faces West; a left turn from West faces South.
After tracing all movements, determine the final position relative to the starting point.
Calculate the net displacement in the North-South and East-West directions. In this case, the North-South displacement is zero (40m North - 40m South = 0), and the East-West displacement is 20m West.

Concept Tested & Keywords

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Practise the full RRB Staff Nurse Kolkata-2015

Attempt every question from this paper in a timed mock, then review the full solution for each one.