Question 889023
Two cars started from the same point traveling in opposite direction. one traveled 
at half the speed of the other. after 5 hours they were 600 km apart. what is the speed of the faster car?
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let x=speed of slower car
2x=speed of faster car
distance=travel time*speed
..
5x+5*2x=600
15x=600
x=40
2x=80
speed of faster car=80 mph