<PRE><B>Question 805452</B>
boat   	speed	=	10	mph														
current     	speed	=	x	mph														
																		
against 	current	=	10	-	x													
with 	current	=	10	+	x 													
																		
Total distance =		11	miles 		Total Time=	5.50	hours  											
Time upstream + time downstream =						5.5	hours  											
																		
11	/(	10	-	x 	)+	11	/(	10	+	x 	)=	5.5						
11	(	10	+	x 	)+	11	(	10	-	x 	)=	5.50	(	100	-	1	X^2	)
110	+	11	x	+	110	-11	x  	=	550	-	5.5	X^2						
220	-	-550	=			-5.5	X^2											
-330	=		-5.5	X^2														
-5.5	X^2=	-330																
X^2	=	60																
X =	+/-	7.75									Ignore negative value
current speed = 7.75 mph			
</PRE>