Question 427544
let speed in still water = 		x	mph				
current speed 3	mph				
..							
upstream speed = x-3	mph		
downstream speed = x+3	mph		
							
Distance upstream=3					
Distance downstream=9					
Time = same							
3/(x-3)=	9/(x+3)
3*(x+3)=	9*(x-3)
3x+3=9x-27
9x-3x=27	+3
6x=30				
/6						
x=5mph