Question 930545
boat   	speed	=	15	mph			
current     	speed	=	x	mph			
							
against 	current	=	15	-	x		
with 	current	=	15	+	x 		
							
Total distance =		36	miles 		Total Time=	5.00	hours  
Time upstream + time downstream =						5	hours  
							
36	/(	15	-	x 	)+	36	/(
36	(	15	+	x 	)+	36	(
540	+	36	x	+	540	-36	x  
1080	-	-1125	=			-5	X^2
-45	=		-5	X^2			
-5	X^2=	-45					
x2=	=	9					
x=   	+/-	3					

3 mph