Question 730998
Boat speed	=	35	mph										
current speed	=	x	mph										
													
speed against	current	35	-	x									
speed with	current	35	+	x									
													
Distance against	current	93	miles										
Distance with	current	117	miles										
													
t=d/r	time against = time with		current	-									
93	/	(	35	-	x	)=	117	/	(	35	+	x	)
93	(	35	+	x 	)=	117	(	35	-x	)			
3255	+	93	x	=	4095	-	-117	x					
117	x	93	x		4095	+	-3255						
210	x	=	840										
/	210												
x	=	4	mph	current	speed