A man is walking at a speed of 10 km/h. After every kilometer, he rests for 5…
2025
A man is walking at a speed of 10 km/h. After every kilometer, he rests for 5 minutes. The time taken to cover a distance of 5 km by the man is :
- A.
30 minutes
- B.
45 minutes
- C.
55 minutes
- D.
50 minutes
Attempted by 6 students.
Show answer & explanation
Correct answer: D
When a journey of several kilometres includes a fixed rest break after each kilometre, the total time equals the pure walking time plus the rest time. Because no rest is needed once the destination is reached, a journey of n kilometres has only (n − 1) genuine rest breaks between kilometres, not n.
Speed = 10 km/h, so time to walk 1 km = 60 minutes ÷ 10 = 6 minutes.
Time to walk the full 5 km = 5 × 6 minutes = 30 minutes.
Rests occur only between consecutive kilometres — after km 1, km 2, km 3 and km 4 — giving (5 − 1) = 4 rest breaks.
Rest time = 4 × 5 minutes = 20 minutes.
Total time = walking time + rest time = 30 minutes + 20 minutes = 50 minutes.
Cross-check: counting a rest after every one of the 5 kilometres (including the last) would add 5 × 5 = 25 minutes to the 30 minutes of walking, giving 55 minutes — but the final rest is not actually taken since the journey ends at that point, so the extra 5 minutes must be removed, bringing the total back down to 50 minutes.