A bird travels 40 km North, then 50 km East, then 110 km North, and finally 50 km West. What is the bird's final position relativ…

Question

A bird travels 40 km North, then 50 km East, then 110 km North, and finally 50 km West. What is the bird's final position relative to its starting point?

1. A. 50 km South
2. B. 150 km North (Correct answer)
3. C. 50 km East
4. D. 120 km South

Correct Answer

Option B — 150 km North

Detailed Solution & Explanation

The correct answer is 150 km North.

Key Points

• This is a direction and distance problem solved by adding displacements along the two axes separately.
• List the moves: 40 km North, 50 km East, 110 km North, 50 km West.
• North–South axis: 40 North + 110 North = 150 km North (no southward move).
• East–West axis: 50 East − 50 West = 0 (they cancel exactly).
• So the net displacement is 150 km North of the start, with no east–west offset.
• treat North/South as the vertical axis and East/West as the horizontal axis. Add same-direction moves, subtract opposite ones, then combine.
• Because the east and west moves are equal, the bird ends up due north.

Exam Tip

• always tabulate the four directions before adding; the final position is 'net vertical' and 'net horizontal', and when one axis cancels, the answer is purely along the other.