Two of three legs cancel — Direction Sense Aptitude Question
Two of three legs cancel: A boy walks 15 m north, 20 m east and 15 m south. How far is he from the start? Answer and worked solution on CodeKairo.
- Topic: Direction Sense
- Section: Logical Reasoning
- Difficulty: Easy
- Time target: 45 seconds
Question
A boy walks 15 m north, 20 m east and 15 m south. How far is he from the start?
Options
- 15 m
- 20 m
- 35 m
- 50 m
Show the answer and the worked solution
Correct answer: B. 20 m
Worked solution
- North 15 and south 15 cancel.
- He is 20 m east of the start.
Answer: 20 m.
The idea
Add up each axis separately before reaching for Pythagoras. Often one axis cancels and no square root is needed.
Shortcut. He has walked three sides of a rectangle, so he is exactly the fourth side, 20 m, from the start.
Common trap. "50 m" — adding all three legs, 15 + 20 + 15, which is the distance walked rather than the displacement.