Please help me this is due in 3 minutes

a

Step-by-step explanation:

Option A (3)

Step-by-step explanation:

Given that Tinh can row at a rate of 6 mph in still water.

Also it takes her 2 hours to row upstream from a dock to a park. She then rows back to the dock, and it only takes 40 minutes.

While upstream she travels against the stream but while downstream she travels along with the stream

Let x  be the speed of boat in still water and y that of stream

Then since distance d is the same, time x speed =D

i.e. (x-y)120 = (x+y)40 after converting hours to minutes

80x=160y

x=2y

x=6 (given)

So y = 6/2=3 mph