A train can cover a certain distance in 3 hrs. If the track management is improved, an increase in the speed of the train by 10 km/h is possible, which can reduce the above journey time by 30 minutes. Find the initial speed of the train.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e 50 km/h
Concept Used :
Distance = Speed × Time
Now, let the initial speed of the train be X km/hr.
So, the distance covered by train in 3 hrs = 3X km ...(i)
Now the increased speed of the train is (X + 10) km/hr.
The decrease in the time of journey = 30 minutes
So the new time = 2 hours 30 minutes = 5/2 hrs.
So the distance covered by new speed = (X + 10) × 5/2 ...(ii)
Now from equation (i) and (ii),
⇒ 3X = (X + 10) × 5/2
⇒ 3X - 5X/2 = 25
⇒ X/2 = 25
⇒ X = 50.
Hence the initial speed of the train is 50 km/hr.