Question 782682
Plane  	speed	=x	mph					
wind   	speed	=y	mph					
against  	wind   	1 1/6	hours					
with	wind   	 5/6	hours					
								
Distance against 		210	miles	distance with 		210	miles	
t=d/r	against	wind   		-				
210.00	/	(	x	-	y	)=	1.17	
1.17	(	x	-	y	)	=	0.83	
1.17	x	-	1.17	y	=	210.00	....................1	
								
210.00	/	(	x	+	y	)=	0.83	
0.83	(	x	+	y	)	=	210.00	
0.83	x	+	0.83	y	=	210.00	...............2	
Multiply (1) by	0.83							
Multiply (2) by	1.17							
we get								
0.97	x	+	-0.97	y	=	175.00		
0.97	x	+	0.97	y	=	245.00		
1.94	x	=	420.00					
/	1.94							
x	=	216	mph					
								
plug value of x in (1)				y				
1.17	x		-1.17	y	=	210.00		
252.00			-1.17	-252.00	=	210.00		
-1.17	y	=	210.00					
-1.17	y	=	-42.00	mph				
	y	=	36					
Plane  	speed	216	mph					
wind   	speed	36	mph