It's not much of a trick question, if it's absolutely trivial. It's cherry picked to show that the AI tries to associate things based on what they look like, not based on the logic and meaning behind them. If you gave the same prompt to a human, they likely wouldn't even think of the original riddle.

Even in your example it starts off by doing absolute nonsense and upon you correcting it by spelling out the result, it finally manages, but still presents it in the format of the original riddle.

You can notice, in my example I intentionally avoid telling it what to do, rather just question the bullshit it made, and instead of thinking "I did something wrong, let's learn", it just spits out more garbage with absolute confidence. It doesn't reason. Like just try regenerating the last answer, but rather ask it why it sent the man back, don't do any of the work for it, treat it like a child you're trying to teach something, not a machine you're guiding towards the correct result.

And yes, people with memory issues immediately suffer on the inteligence side, their lives a greatly impacted by it and it rarely ends well for them. And no, they are not worthless, I never said that they or AI is worthless, just that "machine learning" in its current state (as in how the technology works), doesn't get us any closer to AGI. Just like a person with severe memory loss wouldn't be able to do the kind of work we'd expect from an AGI.