Question

A car travels 60 km/h for 1.5 hours. Then it travels 3 hours at 45 km/h, after that it covers 55 km in 30 minutes, what is the average speed of the car for the entire journey?

• A. 28 km/h
• B. 86 km/h
• C. 56 km/h
• D. 70 km/h

Answer 1

Answer:

C. 56 km/h

Solution: Given: Car travel 1.5 hrs at a speed of = 60 km/h Car travel 3 hrs at a speed of = 45 km/h Car travel 30 minutes to cover the distance = 55 km Concept: Average speed = Total distance/ Total time Calculation: Total distance cover by car in 1.5 hrs at a speed of 60 km/h = (60 × 1.5) = 90 km Total distance cover by car in 3 hrs at a speed of 45 km/h = (45 × 3) = 135 km Total distance cover by car in 30 minutes = 55 km Total distance covered = (90 + 135 + 55) km = 280 km Total time taken = (1.5 + 3 + 0.5) hours = 5 hours Average speed = 280/5 = 56 km/h ∴ Average speed for the whole journey is 56 km/hr