Earlier quoted context omitted.
This might be a good time to look up the definition of axiom: "a statement accepted as true as the basis for argument or inference".
Yes, but I think that's "accepted" in the sense of "until we run into a contradiction", at which point you have to start over with new axioms. I.e. it turned out your axioms weren't all true. I think that in the definition you gave "accepted" should be replaced by "assumed".
The first sentence of that problem is an axiom. It is absolutely 100% true, within the context of that story problem. It could contradict another axiom, but it can't turn out to be false, because it's not a statement about the real world.