<PRE><B>Question 453751</B>
Plane II	x 	mph						
Plane I	x+100						
..								
They are going away from each other.								
								
So add up their speed.								
								
combined speed = x+x+100			
(2x+100	) 			
Time = 	4 hours						
Distance =2000	miles						
Distance = speed * time								
(2x+100	)*4=	2000
8x+400	=2000			
8x=2000	-400			
8x=1600					
/8							
x=200	mph	Plane II					
Plane I	200+100	=300	mph		
								
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