Question 473735
  <pre><font face = "Tohoma" size = 4 color = "indigo"><b> 
Hi,
Let s and c represent the rate of the sailboat(still water) and the rate of
the currecnt respectively
Question states*** Note D = r/t OR r = D/t
 s+c = 20mi/4hr = 5mph
 s-c = 20mi/5hr = 4mph
  2s = 9mph
   s = 4.5mph  and c = .5mph   (5mph- 4.5mph = .5mph)