Two trains are moving in opposite directions at speeds of 60 km/h and 110 km/h. The length of one train is 360 m. The time taken by them to cross each other is 21 seconds.The length (in m) of the other train, correct to 2 decimal places, is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 632.
Speeds: 60 km/h + 110 km/h = 170 km/h → convert to m/s = 170 × (5/18) = 47.222 m/s
Relative speed = 47.222 m/s
Time to cross = 21 seconds
Sum of lengths = (Relative speed × time) = 47.222 × 21 = 992 m
One train = 360 m, so other = 992 − 360 = 632 m
Rounded to two decimals: 632.00 m