Two trains A and B starts from Howrah and Patna towards Patna and Howrah respectively at the same time. After passing each other, they take 4, h, 48 min and 3 h, 20 min to reach Patna and Howrah, respectively. If the train from Howrah is moving at 45 km/h, then the speed of the other train is?
Correct Answer: 54 km/h
Explanation:
Given, a = 45 km/h, y = ?, t1 = 4 h 48 min and t2 = 3 h 20 min
Using y = a√t1 / t2= 45√4 h and 48 min /3 h and 20 min
= 45√(24/5h) / (10/3 h) = 45√24 x 3/5 x 10
= 45 x √1.44 = 45 x 12 = 54 km/h
