Multiple choice

Two train are $2$ km apart and their lengths are $200$ m and $300$ m. They are approaching towards each other with a speed of $20$ m/s and $30$ m/s respectively. After how much time will they cross each other?

  1. $50$ seconds
  2. $100$ seconds
  3. $\displaystyle \frac{25}{3}$ seconds
  4. $150$ seconds
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total distance to cover = 2km + 200m + 300m = 2500m. Relative speed = 20m/s + 30m/s = 50m/s. Time = 2500 / 50 = 50 seconds.

AI explanation

Using the formula for total distance, the trains must cover the initial gap plus their lengths, which is 2000 + 200 + 300 = 2500 m. Since they approach each other, their relative speed is 20 + 30 = 50 m/s. Dividing the total distance by the relative speed gives 2500 / 50 = 50 seconds.

Keep practicing — related questions