Multiple choice general knowledge math & puzzles Find the odd man out. 3, 5, 11, 14, 17, 21 21 14 17 3 Reveal answer Fill a bubble to check yourself B Correct answer Explanation 14 is the odd number because all other numbers (3, 5, 11, 17, 21) are odd numbers, while 14 is an even number. In odd man out questions, you look for the one element that doesn't follow the pattern of the others.