Question 694674
canoe 	speed	x	km/h									
current     	speed	6	km/h									
..												
against currentspeed	x-	6										
withcurrent 	x+	6										
..												
Against current		10	hours									
with current x+y		4	hours									
Distance is same.  D=r*t												
10	(	x	-	6	)	=	4	(	x	+	6	)
10	x	-	60			=	4	x	+	24		
10	x	-	4	x	=		60	+	24			
6	x				=		84					
/	6											
x				=		14	km/h					
canoe 		=	14	km/h