A car taken 5 hours to cover a distance of 300 kms.
How much should the speed in km/hour be maintained to cover the same distance in 4/5th of the previous time ?

Answer: D. 75 km/hour

1st case :
Time taken by car to cover 300 km = 5 hours.
Speed of the car = 300/5 = 60 km/hour.

2nd case :
Time desired to cover the same distance of 300 km = 4 hours.
Required speed = 300/4 = 75 km/hour.