Question 253318
Let the speed of the boat in still water be x miles/h
Let the speed of the current be y miles/h
Given, x-y = 16   ...(1)
Given, An Everglades air boat travels 78 miles downstream in the same amount of time it requires to move upstream a distance of 48 miles. 
So, 78/(x+y) = 48/(x-y)                  [Time = distance/speed)
      78(x-y)= 48(x+y)
      78*16= 48(x+y)
       1248= 48(x+y)
       x+y = 1248/48
       x+y = 26    ...(2)
(1)+(2): 2x = 16+26
         2x = 42
          x = 21
(2)=>  21+y = 26
          y = 26-21
          y = 5 
Therefore the speed of the boat in still water is 21 miles/h
and the speed of the current is 5 miles/h