Question 871365
boat   	speed	=x	mph						
current     	speed	=y	mph						
against  	current     	2.5	hours						
with	current     	0.75	hours						
									
Distance against 		10	miles	distance with 		10	miles		
t=d/r	against	current     		-					
10.00	/	(	x	-	y	)=	2.50		
2.50	(	x	-	y	)	=	0.75		
2.50	x	-	2.50	y	=	10.00	....................1		
									
10.00	/	(	x	+	y	)=	0.75		
0.75	(	x	+	y	)	=	10.00		
0.75	x	+	0.75	y	=	10.00	...............2		
Multiply (1) by	0.75								
Multiply (2) by	2.50								
we get									
1.88	x	+	-1.88	y	=	7.50			
1.88	x	+	1.88	y	=	25.00			
3.75	x	=	32.50						
/	3.75								
x	=	8.67	mph						
									
plug value of x in (1)				y					
2.50	x		-2.50	y	=	10.00			
21.67			-2.50	-21.67	=	10.00			
-2.50	y	=	10.00						
-2.50	y	=	-11.67	mph					
	y	=	4.67						
boat   	speed	8.67	mph						
current     	speed	4.67	mph						
									
m.ananth@hotmail.ca