Question 1202398
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Downstream:  V = v + c  
    where 
        V = total speed, 
        v = speed of boat in still water, and
        c = speed of current

  V = 280mi/14hr = 20mi/hr   

This tells us
   v + c = 20      (1)


For the upstream direction, we subtract the speed of the current:
   v - c = 280/140
   v - c = 2       (2)


Add (1) and (2):  2v = 22 -->  v = 11  -->  c = 9 (plug v=11 into (1) or (2))

Ans:
  Speed of boat in still water is   11mi/hr
  Speed of current is                9mi/hr


This solution does make the assumption that the speed of the boat and the speed of the current add / subtract in a straightforward (linear) manner.