Question 863896
Plane 	speed	=x	mph	(both speeds are same)				
wind  	speed	=y	mph					
against  	wind	5.6	hours					
with	wind	4	hours					
								
Distance against 		2100	miles	distance with 		2100	miles	
t=d/r	against	wind		-				
2100.00	/	(	x	-	y	)=	5.60	
5.60	(	x	-	y	)	=	4.00	
5.60	x	-	5.60	y	=	2100.00	....................1	
								
2100.00	/	(	x	+	y	)=	4.00	
4.00	(	x	+	y	)	=	2100.00	
4.00	x	+	4.00	y	=	2100.00	...............2	
Multiply (1) by	4.00							
Multiply (2) by	5.60							
we get								
22.40	x	+	-22.40	y	=	8400.00		
22.40	x	+	22.40	y	=	11760.00		
44.80	x	=	20160.00					
/	44.80							
x	=	450.00	mph					
								
plug value of x in (1)				y				
5.60	x		-5.60	y	=	2100.00		
2520.00			-5.60	-2520.00	=	2100.00		
-5.60	y	=	2100.00					
-5.60	y	=	-420.00	mph				
	y	=	75.00					
Plane 	speed	450.00	mph					
wind  	speed	75.00	mph					
								
m.ananth@hotmail.ca