Question

Which number doesn't belong?

21, 18, 16, 7, 6
18, 10, 13, 11, 16
2, 16, 9, 7, 17
11, 16, 4, 8, 2
6, 9, 11, 15, 18
19, 9, 14, 8, 11

Answer 1

21

Explanation:

Most of the numbers are within the same range. Then you have 21 which is slightly out of range from the next highest 19.