Very hard IQ induction based problem (Stuck for over 30 mins) in New Logic/Math Puzzles Posted September 11 · Report reply I tried entering a number on a whim to see what would happen. It seems to have taken it. Is it normal to get an error message if you type the wrong answer? 1221. I couldn't tell you why. It seems to fit a pattern if you ignore the 5th set but with it included, I can't explain it.