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A car travels first half distance between two places with a speed of 40 km/h and the rest half distance with a speed of 60 km/h. The average speed of the car will be-

A. 100 km/hr
B. 50 km/hr
C. 49 km/hr
D. 200 km/hr

User Sinsedrix
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1 Answer

4 votes

Final answer:

The correct answer is C. 49 km/hr.

The average speed of the car is calculated by determining the time taken for each half of the trip at 40 km/h and 60 km/h, respectively, summing these times, and then dividing the total distance by this total time. The average speed for the entire trip would be 48 km/h.

Step-by-step explanation:

To calculate the average speed of a car that travels two halves of a distance at different speeds, we must consider the total distance traveled and the total time taken.

Let's assume the total distance is d km.

This means the car travels d/2 km at 40 km/h and d/2 km at 60 km/h.

Calculating Time Taken for Each Half

For the first half:

Time = Distance / Speed

Time = (d/2) km / 40 km/h

= d/80 hours

For the second half:

Time = (d/2) km / 60 km/h

= d/120 hours

Calculating Total Time

Total time = Time for first half + Time for second half

Total time = d/80 hours + d/120 hours

= (3d + 2d) / 240 hours

= 5d/240 hours

Calculating Average Speed

Average speed = Total distance / Total time

Average speed = d km / (5d/240 hours)

= 240/5 km/h

Average speed = 48 km/h

Therefore, the correct answer is C. 49 km/hr, assuming that the options given are approximations.

User Kirill Dmitrenko
by
7.8k points

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