2012 · Q8
Train A is 75 m long and travels at a uniform speed of 54 km/hour. Train B is 125 m long and travels at a uniform speed of 36 km/hour in the direction opposite to that of Train A. If these trains are crossing at a double-track stretch, what is the time taken for the two trains to fully clear each other ?
General Mental Ability, Quantitative Aptitude and StatisticsTime, work and measurement
- A10 seconds
- B8 seconds
- C7.2 seconds
- D6.6 seconds
Explanation
The trains move in opposite directions, so the relative speed is 54 + 36 = 90 km/h = 25 m/s. The distance to be cleared is the sum of the two lengths: 75 + 125 = 200 m. Time = 200/25 = 8 seconds. Using a single train's speed or only one train's length produces the wrong options.