Difficulty: Medium
Correct Answer: North-East
Explanation:
Introduction:
This direction–sense problem describes several moves with precise distances and multiple right and left turns. We need to determine in which direction the person is from the starting point after all movements are completed. Using a coordinate plane and tracking the direction after every turn allows us to find the final position and its direction relative to the origin.
Given Data / Assumptions:
• Initial facing direction: South.• First, turn right and walk 20 m.• Turn right again and walk 10 m.• Turn left and walk 10 m.• Turn right and walk 20 m.• Turn right again and walk 60 m.• Standard compass directions and flat ground are assumed.
Concept / Approach:
We treat the movement as motion on an x–y plane. North corresponds to positive y, South to negative y, East to positive x and West to negative x. Right and left turns specify 90 degree rotations relative to the current facing direction. By updating both the position and facing direction step by step, we can compute the final coordinates and interpret them as a direction from the starting point.
Step-by-Step Solution:
Step 1: Start at (0, 0) facing South.Step 2: Right turn from South points West. Walking 20 m West moves to (−20, 0).Step 3: Right turn from West points North. Walking 10 m North moves to (−20, 10).Step 4: Left turn from North points West. Walking 10 m West moves to (−30, 10).Step 5: Right turn from West points North. Walking 20 m North moves to (−30, 30).Step 6: Right turn from North points East. Walking 60 m East increases the x-coordinate: −30 + 60 = 30, so we reach (30, 30).Step 7: The starting point is (0, 0) and the final point is (30, 30). Thus the person is 30 m to the East and 30 m to the North of the starting position.
Verification / Alternative check:
Because both the x and y coordinates of the final position are positive and equal (30, 30), the final point lies in the first quadrant, exactly diagonally from the origin along the North-East line. The distance is not requested, only the direction, so recognising that both components are positive immediately tells us that the direction from the starting point is North-East.
Why Other Options Are Wrong:
North alone would require no net East–West displacement, but we have 30 m East. East alone would require no net North–South displacement, but we have 30 m North. North-West would require a negative x-component (towards West), which is not the case. South-East would require positive x but negative y, also inconsistent with our final coordinates. Only North-East matches both positive coordinates.
Common Pitfalls:
It is easy to get disoriented when turning from West or South and misidentify right and left. Others forget to update the facing direction correctly at each stage. Keeping a small table of (current direction, movement, new direction, new coordinates) after every instruction or drawing a stepwise path on graph paper significantly reduces the risk of errors.
Final Answer:
From the starting point, the person is finally located towards the North-East direction.
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