540 meters
The velocity of the boat relative to the water;
2 m/s + 1 m/s = 3m/s Â
Time is 3 minutes;
but 1 minute =60 seconds
Therefore; time is = 3 ×60 = 180 seconds
Distance = velocity × time
         = 3 × 180 = 540 m
     = 540 meters