Question

Two trains of lengths 150 metres and 180 metres respectively, are running in opposite directions on parallel tracks. If their speeds are 30 km/hr and 24 km/hr respectively, then the time taken by them to cross each other is:

• A. 22 Seconds
• B. 24 Seconds
• C. 28 Seconds
• D. 30 Seconds

Hint:

For problems involving moving objects, convert all units to the same system (e.g., metres and seconds) and use the relative speed formula to find the time taken to cross each other.

Answer 1

The Correct Option is A

The total length to be crossed by the two trains is: \[ 150 + 180 = 330 \text{ metres} \] Step 1: Convert the speeds into metres per second: \[ 30 \text{ km/hr} = \frac{30 \times 1000}{3600} = 8.33 \text{ m/s} \] \[ 24 \text{ km/hr} = \frac{24 \times 1000}{3600} = 6.67 \text{ m/s} \] Step 2: The relative speed of the two trains is: \[ 8.33 + 6.67 = 15 \text{ m/s} \] Step 3: The time taken to cross each other is: \[ \text{Time} = \frac{\text{Total Length}}{\text{Relative Speed}} = \frac{330}{15} = 22 \text{ seconds} \] Thus, the time taken by the trains to cross each other is 22 seconds.