Question 731646
rowing	speed	=x	mph					
current     	speed	=y	mph					
against 	current     	3	hours					
with 	current     	2	hours					
								
Distance with	current     	20	miles		distance against	current     	12	
t=d/r	against	current     	(x-y)					
12.00	/	(	x	-	y	)=	3.00	
								
3.00	x	-	-3.00	y	=	12.00	....................1	
with	current     	(x+y)						
20.00	/	(	x	+	y	)=	2.00	
2.00	(	x	+	y	)	=	20.00	
2.00	x	+	2.00	y	=	20.00	...............2	
Multiply (1) by	2.00							
Multiply (2) by	3.00							
we get	2.00							
6.00	x	+	-6.00	y	=	24.00		
6.00	x	+	6.00	y	=	60.00		
12.00	x	=	84.00					
/	12.00							
x	=	7	mph					
								
plug value of x in (1)				y				
3	x		-3	y	=	12		
21			-3	-21	=	12		
-3	y	=	12					
-3	y	=	-9	mph				
	y	=	3					
rowing	7	mph						
current     	3	mph