2024 · Q75
If the lengths of the two trains A and B are 400 m and 500 m respectively, then what is the time taken by them to cross each other?
Elementary MathematicsTime, Speed and Distance
- A21.6 seconds
- B18.2 seconds
- C17.4 seconds
- D15.4 seconds
Explanation
The two trains approach each other at 60 + 90 = 150 km/h, i.e. 150 × 5/18 = 125/3 m/s. Crossing requires covering 400 + 500 = 900 m. This takes 900 ÷ (125/3) = 21.6 s, option (a).