A train is running at 60 km/hr. How much time will it require to cross a 2 km bridge?

Appeared in: AIIMS Delhi NO - 2018

Explanation

The fundamental formula to solve this problem is Time = Distance / Speed.
Given the distance of 2 km and a speed of 60 km/hr, the time taken is calculated as 2 km / 60 km/hr, which equals 1/30 of an hour.
To match the units in the options, the time in hours must be converted to minutes by multiplying by 60.
The final calculation is (1/30) hours × 60 minutes/hour, which results in 2 minutes.

Option A: If the train took 20 minutes (or 1/3 of an hour) to travel 2 km, its speed would be 6 km/hr (2 km / 0.333 hr), which contradicts the given speed of 60 km/hr.
Option B: If the train took 10 minutes (or 1/6 of an hour) to travel 2 km, its speed would be 12 km/hr (2 km / 0.167 hr), which is incorrect.
Option C: If the train took 60 minutes (1 hour) to travel 2 km, its speed would be only 2 km/hr, which is far from the stated 60 km/hr.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculation of time using speed and distance as background academic context rather than a clinical decision trigger.
While this is a general aptitude question, the underlying skill of rate calculation is critical in nursing practice.
Nurses frequently perform similar calculations for IV drip rates (e.g., mL/hour), medication administration timing, and assessing rates of change in a patient's vital signs.
Accuracy in these calculations is paramount for patient safety, preventing medication errors and ensuring therapeutic effectiveness.

How to Approach the Question

First, identify the given parameters from the question: Speed = 60 km/hr and Distance = 2 km.
Recall the fundamental formula that connects these three variables: Time = Distance / Speed.
Substitute the known values into the formula: Time = 2 / 60.
Perform the calculation. The result will be in hours (1/30 hours) because the speed is in km/hr.
Check the units of the options, which are in minutes. Convert your calculated time from hours to minutes by multiplying by 60.
Select the option that matches your final calculated result (2 minutes).

Concept Tested & Keywords

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Practise the full AIIMS Delhi NO - 2018

Attempt every question from this paper in a timed mock, then review the full solution for each one.