Hmmm… I was looking at the fish question (post #893) just now to once again admire ChatGPT’s handiwork. I was taking these questions out of IQ tests and throwing them at ChatGPT without necessarily looking at them very closely. I just realized that this one is something in the nature of a trick question in that it’s actually much simpler than it appears to be. ChatGPT got the right answer, but it took the long way around. There’s no need to set up a system of equations.
The thing that a perceptive individual would recognize about this question is that each of the series of five comparative statements immediately rules out one of the fish. The first one immediately rules out option “A”. The second one rules out B. The third one rules out D. The fourth one rules out E. Bingo! One can immediately see that the lightest fish must be C. The fifth statement is redundant and is probably just there for obfuscation.
The key to doing well on an IQ test is not just getting the right answers, but getting them quickly on the simple questions so you have time to spend on the harder ones and still finish the test on time.