---------------------------------
|     |faster|rate|time|distance|
---------------------------------
|boat1| 0.0  |    | 3.0|        |
---------------------------------
|boat2| 9.0  |    | 3.0|        |
---------------------------------
|total|      |    |    |  129.0 |
---------------------------------

rate$ = (total distance - boat2 time X boat2 faster) / (boat2 time + boat1 time); for boat1 and boat2: distance$ = (rate$ + faster$) X time$. This problem uses default values to achieve plural processing.