A car runs for one hour with a speed 60 km per hour, for 2 hours with a speed 70 km per hour and for 5 hours with a speed 50 km per hour. What is the average speed of the car in km per hour?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 56.25.
Total distance = 1 × 60 + 2 × 70 + 5 × 50 = 60 + 140 + 250 = 450 km
Total time = 1 + 2 + 5 = 8 hours
Average speed = 450 ÷ 8 = 225/4 = 56.25 km/hr