A person travels in a car for 600 km at an average speed of 50 km/h and 100 km at 100 km/h, and finally reaches his destination by travelling 50 km at a speed of 25 km/h. Determine the average speed during the whole journey.

Correct option is A

Given:

The total distance covered is 600 km, 100 km, and 50 km.

​The speeds for each segment of the journey are 50 km/h, 100 km/h, and 25 km/h respectively.

Formula used:

​$$\text{ Average Speed}=\frac{\text{Total Distance}}{Total \  Time}$$​​

Solution:

​Total distance = 600  + 100  + 50  = 750 km

Total time = 12 hours + 1 hour + 2 hours = 15 hours

Average speed = $$\frac{750}{15}$$​ = 50 km/h

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