Alvin wants to know what his average paddling rate was for a canoe trip to a campsite. On the way there it took him 11 hours against a river current of 3 km/ hr. On the way back, the same distance took him 6 hours with the same 3 km/hr current.

Let
r
= Alvin's average paddling rate. Express the rates against the current and with the current in terms of
r
to complete the below table.

Distance Rate Time
Against the current
d


With the current
d



Using the information summarized in the above table, set up an equation to solve for Alvin's average paddling rate
r
.


Alvin's average paddling rate was
km/hour (If needed, round to 2 decimal places).