Ardi and Lei are both travelling by train.
Ardi’s train travels 70 km in 35 minutes.
Lei’s train travels 585 km.
It leaves at 9:05 and arrives at 13:35.
Work out the difference, in km/h, between the average speed of their trains.
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Answer:
10 kilometer/hour
Step-by-step explanation:
Average speed = Total distance travelled / Total time taken
Ardi:
Total distance travelled = 70 km
Total time taken = 35 minutes = 35/60 hour
Average speed = Total distance travelled / Total time taken
= 70 km ÷ 35/60 hr
= 70 × 60/35
= 4,200/35
= 120 kilometer/hour
Lei:
Total distance travelled = 585 km Total time taken = 9:05 – 13:35 = 4 hours 30 minutes
= 4.5 hours
Average speed = Total distance travelled / Total time taken
= 585 km / 4.5 hours
= 130 kilometer/hour
Difference, in km/h, between the average speed of their trains = Lei’s train – Ardi’s train
= 130 kilometer/hour – 120 kilometer/hour
= 10 kilometer/hour