Question

\(N\) walks \(40\) m East, then turns right and walks \(20\) m, then turns right and walks \(20\) m, then turns left and walks \(10\) m, and finally turns right and walks \(20\) m. How far is \(N\) from the starting point?

• A. \(50\) m
• B. \(30\) m
• C. \(40\) m
• D. \(60\) m

Hint:

Cancel East-West and North-South movements separately before finding final distance.

Answer 1

The Correct Option is B

Concept:
In direction-distance questions, opposite directions cancel each other. We separately calculate East-West and North-South displacement.

Step 1: First movement. \[ 40\text{ m East} \]

Step 2: Second movement. Facing East, right side is South. So, \[ 20\text{ m South} \]

Step 3: Third movement. Now facing South, right side is West. So, \[ 20\text{ m West} \] East displacement becomes: \[ 40-20=20\text{ m East} \]

Step 4: Fourth movement. Now facing West, left side is South. So, \[ 10\text{ m South} \] Total South displacement: \[ 20+10=30\text{ m South} \]

Step 5: Fifth movement. Now facing South, right side is West. So, \[ 20\text{ m West} \] East-West displacement becomes: \[ 20-20=0 \]

Step 6: Final distance. Only South displacement remains: \[ 30\text{ m} \] So the distance from the starting point is \[ 30\text{ m} \]

Step 7: Final answer. \[ \boxed{30\text{ m}} \]