A car travels a distance of 75 km at the speed of 25km/ hr. It covers the next 25 km of its journey at the speed of 5 km/hr and the last 50 km of its journey at the speed of 25 km/ hr. What is the average speed of the car? 

(a) 40 km/hr (b) 25km/hr (c) 15 km/hr (d) 12.5km/hr (e) None of these

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1 Answers

 (c) Time taken to cover first 75 km of distance

=75/25 =3 hours

Time taken to cover next 25 km of distance

=25/5 =5 hours

Time taken to cover last 50 km of its journey

=50/25 = 2 hours

Total distance = 75 + 25 + 50 = 150 km 

Total time taken = 3 + 5 + 2 = 10 hours

Average speed = 150/10 =15 kmph.

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