A Car covers the first 40 km of a journey at a speed of 20km/h and next 60 km…
2024
A Car covers the first 40 km of a journey at a speed of 20km/h and next 60 km at 30 km/h. What is the average speed (inkm / h) of the car for the entire journey?
- A.
25
- B.
12
- C.
20
- D.
16
Attempted by 77 students.
Show answer & explanation
Correct answer: A
Solution: Compute the average speed for the entire journey.
Total distance = 40 km + 60 km = 100 km.
Time for first part = 40 ÷ 20 = 2 hours.
Time for second part = 60 ÷ 30 = 2 hours.
Total time = 2 + 2 = 4 hours.
Average speed = total distance ÷ total time = 100 ÷ 4 = 25 km/h.
Therefore the average speed for the entire journey is 25 km/h.