Q. A car travels 150 km in 2 hours and then 100 km in 1 hour. What is the average speed of the car for the entire trip? (2020)
A.75 km/h
B.80 km/h
C.85 km/h
D.90 km/h
Solution
Total distance = 150 + 100 = 250 km. Total time = 2 + 1 = 3 hours. Average speed = Total distance / Total time = 250 km / 3 hours = 83.33 km/h, which rounds to 80 km/h.
Q. A train travels 60 km at a speed of 30 km/h and then 90 km at a speed of 60 km/h. What is the average speed of the train for the entire journey? (2021)
A.40 km/h
B.45 km/h
C.50 km/h
D.55 km/h
Solution
Total distance = 60 + 90 = 150 km. Time for first part = 60/30 = 2 hours. Time for second part = 90/60 = 1.5 hours. Total time = 2 + 1.5 = 3.5 hours. Average speed = Total distance / Total time = 150 / 3.5 = 42.86 km/h, which rounds to 45 km/h.
