math urgent
posted by mandy .
a motorboat takes 4 hrs to travel 256 miles going upstream. the return trip takes 2 hours going down stream. what is the rate of the boat in still water and what is the rate current.
rate of the boat in still water=mi/hr
rate of the current=mi/hr

rate in still water  x mph
raate of current  y mph
#1: 4(xy) = 256
xy = 64
#2: 2(x+y) = 256
x+y = 128
add them .....
I will let you finish, let me know what you get.
(BTW, the rates seem very unreasonable as you will see) 
8...? not sure..

96...? ahah..
still unsure.