Question 567285
Boat 	speed	=x	mph				
current   	speed	=y	mph				
against  current x-y		50.00	hours				
with current x+y		20.00	hours				
							
Distance = same=		500	km				
t=d/r							
500	/	(	x	-	y	)=	50.00
50	(	x	-	y	)	=	500.00
50	x		-50	y	=	500	....................1
500	/	(	x	+	y	)=	20.00
20.00	(	x	+	y	)	=	500
20.00	x	+	20.00	y	=	500	...............2
Multiply (1) by 	2						
Multiply (2) by	5						
we get							
100	x		-100	y	=	1000	
100	x	+	100	y	=	2500	
200	x	=	3500				
/	200						
x 	=	17.5	mph				
							
plug value of x in (1)							
50	x		-50	y	=	500	
875			-50	y	=	500	
-50	y	=	500	-875			
-50	y	=	-375				
	y	=	7.5				
The speed of  	Boat 	=	17.5	mph			
The speed of  	current   	=	7.5	mph			
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