Question 863478
Boat speed	=	6	km/h										
current speed	=	x	km/h										
													
speed against	current	6	-	x									
speed with	current	6	+	x									
													
Distance against	current	8	miles										
Distance with	current	16	miles										
													
t=d/r	time against = time with		current	-									
8	/	(	6	-	x	)=	16	/	(	6	+	x	)
8	(	6	+	x 	)=	16	(	6	-x	)			
48	+	8	x	=	96	-	-16	x					
16	x	8	x		96	+	-48						
24	x	=	48										
/	24												
x	=	2	km/h	current	speed