Lokesh travels 384 km at 96 km/hr, the next 220 km at 55 km/hr and the next 180 km at 20 km/hr. What is his average speed (in km/hr) for the whole journey? (correct to two decimal places)

1. A

   46.12

2. B

   52.92

3. C

   47.21

4. D

   49.29

Appeared in: Bihar NHM CHO-2025

Explanation

• The formula for average speed is Total Distance divided by Total Time.
• First, calculate the total distance traveled: 384 km + 220 km + 180 km = 784 km.
• Next, calculate the time taken for each segment of the journey: Time = Distance / Speed.
• Time for each part: (384/96) = 4 hours; (220/55) = 4 hours; (180/20) = 9 hours.
• The total time taken for the entire journey is the sum of the individual times: 4 + 4 + 9 = 17 hours.
• Finally, calculate the average speed: 784 km / 17 hours = 46.1176... km/hr, which rounds to 46.12 km/hr.

Why Other Options Were Wrong

• Option B: This value is incorrect and likely results from a miscalculation, such as an error in summing the distances or the calculated times.
• Option C: This value is incorrect. It may arise from attempting to average the speeds directly, which is a common mistake, or from other calculation errors.
• Option D: This value is incorrect and is the result of a mathematical error during the calculation of total distance, total time, or the final division.

Related Visual

• Visual 1: Flowchart: Illustrating the step-by-step process to calculate average speed. 1. Sum individual distances to get Total Distance. 2. Calculate time for each segment (Time = Distance/Speed). 3. Sum individual times to get Total Time. 4. Divide Total Distance by Total Time.

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Calculation of Average Speed as background academic context rather than a clinical decision trigger.
• This question assesses fundamental mathematical aptitude, a skill necessary for various calculations in nursing, such as drug dosage, IV drip rates, and intake/output monitoring.
• While not a direct clinical scenario, the logical reasoning and precision required are transferable to clinical practice.
• What if the question asked for the average of the speeds? The answer would be (96 + 55 + 20) / 3 = 57 km/hr. This is incorrect because the person did not spend an equal amount of time traveling at each speed.

How to Approach the Question

• First, identify the core task: calculate the 'average speed' for the entire journey.
• Recall the correct formula: Average Speed = Total Distance / Total Time.
• Calculate the total distance by adding the distances of all three parts of the journey.
• For each part, calculate the time taken using the formula: Time = Distance / Speed.
• Sum the time taken for all parts to find the total time of the journey.
• Divide the total distance by the total time to find the average speed.

Concept Tested & Keywords

• Concept Tested: Calculation of Average Speed
• Stem keywords: travels, 384 km, 96 km/hr, 220 km, 55 km/hr, 180 km, 20 km/hr, average speed
• Lead-in keywords: What is
• Negative lead-in flag: false

Question ID

Q0xmbJoio-kxqwc8eqHmoB

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