How Do You Solve This ‘rigid Object’-torque Problem? (it Doesn’t Give The Mass Of The Garden Tool)?

A gardening tool uses leverage from a hand to pull weeds. If a 1.3 N*m torque (about the pivot point) is required to pull a given weed, what force did the weed exert on the tool?
I know that you have to add the torque for the stick since the pivot is not in the middle (.13cm x weight of stick) but it still seems like I have 3 unknowns.
Here’s a diagram (the o is the pivot):
(Weed)–.04m–o———-.22m——-(F of hand)
I know this seems like quite alot but I have no clue how to break this problem. I’d appreciate it very much if I got the general process of solving this instead of the answer. Please and thanks!