Question 837616
boat   	speed	=x	mph					
current     	speed	=y	mph					
against  	current     	10	hours					
with	current     	6	hours					
								
Distance against 		210	miles	distance with 		210	miles	
t=d/r	against	current     		-				
210.00	/	(	x	-	y	)=	10.00	
10.00	(	x	-	y	)	=	6.00	
10.00	x	-	10.00	y	=	210.00	....................1	
								
210.00	/	(	x	+	y	)=	6.00	
6.00	(	x	+	y	)	=	210.00	
6.00	x	+	6.00	y	=	210.00	...............2	
Multiply (1) by	3.00							
Multiply (2) by	5.00							
we get								
30.00	x	+	-30.00	y	=	630.00		
30.00	x	+	30.00	y	=	1050.00		
60.00	x	=	1680.00					
/	60.00							
x	=	28.00	mph					
								
plug value of x in (1)				y				
10.00	x		-10.00	y	=	210.00		
280.00			-10.00	-280.00	=	210.00		
-10.00	y	=	210.00					
-10.00	y	=	-70.00	mph				
	y	=	7.00					
boat   	speed	28.00	mph					
current     	speed	7.00	mph					
								
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