 #1
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 5
Homework Statement:

This week's question
A race car driver travels x km at 40km/h and y km at 50 km/h. The total time taken is 2.5 hrs. If the time to travel 6x km at 30km/h and 4y km at 50km/h is 14 hrs. Find x and y
Relevant Equations:

Speed = distance /time
Ave speed = total distance/ total time
Ave speed= (speed 1 + speed 2 ) /2
I get two different answers even the area of the graph.
I think there is something wrong with the equation I constructed for average speed part.
I know the method 1 is correct. But I'd like to know why the average speed cannot be used. And why I get two different areas for the graph
Thank you