<PRE><B>Question 896523</B>
Traveling downstream a certain boat went 17 km/h.
 Traveling upstream it only went 5 km/h.
 What is the speed of the current?
 How fast would the boat go if there were no current?
:
let s = the boat speed in still water
let c = the rate of the current
then a simple equation for each way
s + c = 17
s - c =  5
-------------Adding eliminates c, find s
2s = 22
s = 22/2
s = 11 km/h in still water
then
11 + c = 17
c = 17 - 11
c = 6 km/h is the rate of the current
:
:
Check this in the 2nd equation
11 - 6 = 5</PRE>