The rate is 27 minutes per mile.
Here is the rate of 54 minutes to swim 2 miles expressed at a unit rate:
To express the rate of 54 minutes to swim 2 miles at a unit rate, we need to determine the amount of time it takes to swim one mile. We can do this by dividing the total time (54 minutes) by the total distance (2 miles):
Time per mile = Total time / Total distance
Time per mile = 54 minutes / 2 miles
Time per mile = 27 minutes/mile
Therefore, it takes 27 minutes to swim one mile at this rate.