North, then two left turns — Aptitude Question
North, then two left turns: A man goes 5 km north, turns left and goes 3 km, then turns left and goes 5 km. Answer and worked solution on CodeKairo.
- Topic: Direction Sense
- Section: Logical Reasoning
- Difficulty: Medium
- Time target: 60 seconds
Question
A man goes 5 km north, turns left and goes 3 km, then turns left and goes 5 km. Where is he relative to the start?
Options
- 3 km east
- 3 km west
- 5 km west
- 8 km west
Show the answer and the worked solution
Correct answer: B. 3 km west
Worked solution
- North 5 km, then left (west) 3 km, then left (south) 5 km.
- North and south cancel.
- He is 3 km west of the start.
Answer: 3 km west.
The idea
The mirror of the previous question. Getting the first turn right decides everything that follows.
Shortcut. Two lefts reverse his heading, so the 5 km legs cancel; the 3 km leg points left of north, which is west.
Common trap. "3 km east" — turning left from north to east by mistake; facing north, the left hand points west.