Question

Find the time taken by 180 M long train running at 54 km/hr to cross a man standing on a platform ?

• A. 4 seconds
• B. 12 seconds
• C. 30 seconds
• D. 15 seconds

Answer 1

Answer:

B. 12 seconds

1. Understand the Scenario:
   When a train crosses a standing man, the distance it needs to cover is equal to its own length.

   • $\text{Distance} = 180\text{ metres}$

2. Convert Speed from km/hr to m/s:
   To match the distance in metres, convert the speed by multiplying it by $\frac{5}{18}$:
   $\text{Speed} = 54 \times \frac{5}{18} = 3 \times 5 = \mathbf{15\text{ m/s}}$

3. Calculate Time:
   Use the standard time-distance formula:
   $\text{Time} = \frac{\text{Distance}}{\text{Speed}}$

4. $\text{Time} = \frac{180}{15} = \mathbf{12\text{ seconds}}$