Question 920302
plane	speed	=x	mph					
wind speed given	speed	=y	mph					
against  	wind speed given	4	hours					
with	wind speed given	3  1/ 3	hours					
								
Distance against 		1000      	miles	distance with 		1000      	miles	
t=d/r	against	wind speed given		-				
1000      	/	(	x	-	y	)=	4      	
4      	(	x	-	y	)	=	3  1/ 3	
4      	x	-	4      	y	=	1000      	....................1	
								
1000      	/	(	x	+	y	)=	10/ 3	
3  1/ 3	(	x	+	y	)	=	1000      	
10x		+	10y	=	3000  
x+y=300    	...............2	
Multiply (2) by	4							
      							
we get								
4x		-4	y	=	1200
add to (1)
8x=2200
/8		
x	=	275      	mph					
	plug x in the eqution to get y
x+y=300
275+y=300
y=300-275							
	y	=	25.00					
plane	speed	275.00	mph					
wind speed given	speed	25.00	mph