Without stoppages a train travels a certain distance with an average speed of…
2025
Without stoppages a train travels a certain distance with an average speed of 80 km/h and with stoppages with an average speed of 60 km/h. How many minutes per hour does the train stops ?
- A.
12min
- B.
20min
- C.
15min
- D.
10min
Attempted by 3 students.
Show answer & explanation
Correct answer: C
Answer: 15 minutes.
Step-by-step reasoning:
Let T be the minutes the train stops in each hour.
Running time per hour = 60 - T minutes = (60 - T)/60 hours.
Distance covered in one hour (including stops) = running speed × running time = 80 × (60 - T)/60 km.
This distance must equal the effective average speed with stoppages (60 km) in one hour, so set up the equation: 80 × (60 - T)/60 = 60
Solve: 80(60 - T) = 60 × 60 → 60 - T = 45 → T = 15 minutes.
Therefore the train stops 15 minutes each hour.