Question 670469
Plane 	speed	=x	mph					
wind   	speed	=y	mph					
against  	wind   	3	hours					
with	wind   	45/19	hours					
								
Distance against 		450	miles	distance with wind 		450	miles	
t=d/r	against	wind		-				
450	/	(	x	-	y	)=	3	
3	(	x	-	y	)	=	450	
3	x	-	3	y	=	450	
x-y=150....................1	
								
450	/	(	x	+	y	)=	45/19	
45/19	(	x	+	y	)	=	450	
45/19	x	+	45/19	y	=	450	
x+y=190...............2	

add the two equations (1) & (2)
2x=340
/2
x=170  speed of plane

Therefore speed of wind = 20 mph