Riddle 1. Since we know that they “* aren’t both trustworthy” it limits us to:
1)coin 1 is trustworthy and coin 2 is not
2) coin 1 is not and coin 2 is
3) coin 1 and coin 2 are not trustworthy.
I went 50% b/c 1 and 2 are essentially the same outcome, so it’s between 1/2 and 3. I suppose you could argue that it’s 33%
Or you could you use semantics and say its zero percent.

33% is the correct answer. Indeed the possibilities are:

A is trustworthy & B is trustworthy

A is NOT trustworthy and B is trustworthy

A is trustworthy and B is trustworthy

A is NOT trustworthy and B is NOT trustworthy.

possibility (1) is known to be impossible. Thus of the three possibilities, one of them places A and B as not trustworthy. Thus the probability is 1/3 or 33%. Congrats to @randy for reasoning through it first and @daskljregnxjs for also getting it right!