Nancy can row 20 km downstream in 2 hours, and 4 km upstream in 2 hours. Her pace of rowing in still water and the speeds of the current are_______ and _______ respectively.

Let, Speed of Nancy in still water = x km/hr 

Speed of Stream = y km/hr 

Now, pace of Nancy, during, 

Downstream = x + y km/h 

Upstream = x – y km/h 

As per the question given, 

2(x+y) = 20 

Or x + y = 10                             ____(1) 

And 2(x-y) = 4 

Or x – y = 2                                 ___(2) 

Adding the equations, we get, 

2x = 12, or,

x = 6 

Putting the value of x in equation (1), we get, 

y = 4 

Therefore, 

Speed of Nancy in still water = 6 km/hr 

Speed of Stream = 4 km/hr