Those trick questions bother and amuse me equally. Because they're meant to trick someone into giving a false answer, the question itself tends to be equally incorrect. In this case, there's little relation at all between the four actors; bomb, banana, tree and monkey. It's actually quite plausible for there to be a banana in the tree, or perhaps below the tree, since it is strongly suggested that the monky is in fact headed for a banana, yet is climbing a tree. But the question itself is flawed because of how vague it is. There is no way of answering it correctly, even ignoring the whole banana tree issue.
It's like asking this: It's raining outside. Rox is writing a far too analytical post about something trivial because he has absolutely nothing better to do. How long before he gets wet?
There's an obvious relation between the factors, but absolutely nothing to determine the answer. In the original question, the only thing you actually know is that there is a tree that will explode, and a monkey is climbing it. I'm writing a post, and it's raining. What the question fails to imply is that I'm sitting inside a house, so I'll likely never get wet. Similarly, the trick question fails to mention anything about time, or if the bomb is even set with a timer or fuse to begin with, so there's no way at all of answering it correctly. Since all answers should therefor be assumed incorrect, it's kinda pointless to point out that there's no such thing as a banana tree - when it's clearly stated that the monkey is, in fact, headed for a banana while in a tree.
And still, my post remains strawberry bush sized.