A car travels the first one-third of a certain distance with a speed of 15 km/hr, the next one-sixth of the distance with a speed of 20 km/hr, and the remaining distance with a speed of 30 km/hr.

Consider the following statements:

Statement I: The total time taken for the entire journey is the sum of the times taken for each segment of the trip.
Statement II: The average speed for the entire journey is calculated by dividing the total distance by the total time.

Select the correct answer from below:

(a) Only Statement I is correct.
(b) Only Statement II is correct.
(c) Both statements I and II are correct.
(d) None of the statements is correct.

Question

A car travels the first one-third of a certain distance with a speed of 15 km/hr, the next one-sixth of the distance with a speed of 20 km/hr, and the remaining distance with a speed of 30 km/hr.

Consider the following statements:

Statement I: The total time taken for the entire journey is the sum of the times taken for each segment of the trip.
Statement II: The average speed for the entire journey is calculated by dividing the total distance by the total time.

Select the correct answer from below:

(a) Only Statement I is correct.
(b) Only Statement II is correct.
(c) Both statements I and II are correct.
(d) None of the statements is correct.

ONLiNE UPSC · Accepted Answer

The car travels the first one-third of a certain distance with a speed of 15 km/hr, the next one-sixth of the distance with a speed of 20 km/hr, and the remaining distance with a speed of 30 km/hr.

Let the total distance be D. The total time taken for the journey is the sum of the times taken for each segment.

Statement I is correct.

The average speed is calculated by dividing the total distance by the total time. 

So, Statement II is also correct.

Therefore, option c is correct.

Speed, Time and Distance

Average Speed Calculation

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