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)
Practice Questions
1 question
Q1
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)
40 km/h
45 km/h
50 km/h
55 km/h
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.
Questions & Step-by-step Solutions
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Q
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)
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.
