A man started walking from his house towards south. After walking 6 km, he…
2014
A man started walking from his house towards south. After walking 6 km, he turned to his left and walked 5 km. Then he walked further 3 km after turning left. He then turned to his left and continued his walk for 9 km. How far is he away from his house ?
- A.
3 km
- B.
4 km
- C.
5 km
- D.
6 km
Attempted by 20 students.
Show answer & explanation
Correct answer: C
Key idea: convert the walk into coordinates (take the house as origin) and compute the straight-line distance.
Step 1: Start at (0, 0). Walk 6 km south → position (0, −6).
Step 2: Turn left (east) and walk 5 km → position (5, −6).
Step 3: Turn left (north) and walk 3 km → position (5, −3).
Step 4: Turn left (west) and walk 9 km → position (5 − 9, −3) = (−4, −3).
Distance from the house = √( (−4)² + (−3)² ) = √(16 + 9) = √25 = 5 km.
Final answer: 5 km.