You get one month to prepare. For the geese, you only can use your bare hands and all three will come at you at the same time. For the bear, you can use any one weapon invented before 500 AC.
You receive $100,000 for each goose killed, or $10,000,000 if you kill the bear.
I’m imagining you both being released into a gladiator style arena
Oh, well even easier then. The Colosseum’s floor is already hollow, and at one point in its history they removed the floor panels and filled it up with water to re-enact naval battles. All I need to do is prep a line across it as a moat, fill it with the flammable mixture, then chuck a torch into it.