Question

A car takes 45 minutes to cover a distance of 30 km. In order to cover the same distance in 5 minutes less time, what is the increase in the speed of the car?

• A. 2.5 km/hr
• B. 3 km/hr
• C. 4.5 km/hr
• D. 5 km/hr

Answer 1

Answer:

D. 5 km/hr

Speed = Distance/Time Initial speed of car = 30/(45/60) = 40 km/hr When car takes 5 min. less time, time taken = 45 - 5 = 40 min. = 40/60 = 2/3 hrs. Speed of car = 30/(2/3) = 45 km/hr Speed of car is increased by = 45 - 40 = 5 km/hr