Amit starts driving from point A and drives 13 km towards North. Then he turns…
2025
Amit starts driving from point A and drives 13 km towards North. Then he turns right and drives 11 km, then turns right and drives 17 km. Then he turns right and drives 15 km. Finally, he turns right and stops at point P after driving 4 km. How much distance (shortest distance) and in which direction does he need to drive to reach point A again? (Until specified, all turns are 90 degree turns only)
- A.
5 km, towards West
- B.
4 km, towards East
- C.
4 km, towards West
- D.
5 km, towards East
Attempted by 12 students.
Show answer & explanation
Correct answer: B
In a direction-sense route-tracing problem, plot every straight-line leg on an X-Y grid with East as the positive x-axis and North as the positive y-axis; a “turn right” always rotates the direction of travel 90° clockwise through the cycle North → East → South → West → North. Once the final point is plotted, the shortest way back to the start is the straight-line distance between the two points, and its direction follows from the sign of the horizontal (east-west) and vertical (north-south) gap between them.
Take A as the origin (0, 0). Travel North 13 km, reaching (0, 13).
Turn right (North → East) and travel East 11 km, reaching (11, 13).
Turn right (East → South) and travel South 17 km, reaching (11, −4).
Turn right (South → West) and travel West 15 km, reaching (−4, −4).
Turn right (West → North) and travel North 4 km, reaching P at (−4, 0).
Compare P(−4, 0) with A(0, 0): both share the same north-south coordinate (0), so there is no residual north-south gap; the east-west coordinates differ by 4, with P sitting 4 km to the west of A.
As an independent check, total the north-south and east-west legs separately instead of plotting points: the north-south legs are +13 (North), −17 (South), +4 (North), which sum to 0 — confirming P is level with A. The east-west legs are +11 (East), −15 (West), which sum to −4 — confirming P is 4 km west of A. Both methods agree.
Since P is 4 km west of A with no north-south offset, the shortest way back from P to A is 4 km towards the East.