The current is 1/30 miles per minute.
Wait no! I did not account for the current on the way back.
As Rosalind Rowe rowed up-stream on the Raritan River, she noticed a piece of driftwood floating by. She continued rowing upstream for half an hour, when she suddenly decided that her husband would like the driftwood. Rosalind quickly turned around, headed downstream after the driftwood and caught up to it 2 miles downstream of the spot at which she originally saw it. Assuming that Rosalind maintained a constant rate of rowing throughout, how fast was the current in the river?