A train is moving at a speed of 90 km/h. How many seconds will it take to cover a distance of 2275 m?

Introduction / Context:
This speed, distance, and time question asks how long a train moving at a constant speed takes to cover a fixed distance. Problems of this type are very common in aptitude tests and require careful unit conversion and straightforward formula application.

Given Data / Assumptions:

• Speed of train = 90 km/h.
• Distance to be covered = 2275 m.
• The train moves at a constant speed in a straight line.
• Required answer is in seconds.

Concept / Approach:
The key relationship is time = distance / speed. To keep units consistent, we convert the speed from km/h to m/s so that the distance in metres divided by speed in metres per second gives time in seconds directly. Then we perform a simple division to get the final result.

Step-by-Step Solution:
Step 1: Convert speed from km/h to m/s using 1 km/h = 5/18 m/s. Step 2: Speed in m/s = 90 * 5 / 18 = 25 m/s. Step 3: Distance to be covered = 2275 m. Step 4: Use time = distance / speed, so time = 2275 / 25 seconds. Step 5: Compute 2275 / 25 = 91 seconds.

Verification / Alternative check:
We can verify by multiplying back. At 25 m/s, in 91 seconds the train covers 25 * 91 = 2275 m, exactly matching the given distance. The numbers are clean and the units are consistent, which confirms that our time calculation is correct.

Why Other Options Are Wrong:

• 96 seconds: This implies a covered distance of 25 * 96 = 2400 m, which is greater than 2275 m.
• 86 seconds: This would give 25 * 86 = 2150 m, less than the required distance.
• 93 seconds: At this time, distance would be 25 * 93 = 2325 m, again not equal to 2275 m.

Common Pitfalls:
Mistakes often occur when converting from km/h to m/s, especially reversing the conversion factor. Another error is rounding too early, which can give slightly off results. Here, the division 2275 by 25 is exact and should be computed carefully to avoid arithmetic mistakes.

Final Answer:
The train will take 91 seconds to cover 2275 m.