
The number that doesn’t belong is 31.
Why?
All the other numbers (12, 18, 24, 46) are even, while 31 is odd.
Also, 31 is the only prime number in the list.

The number that doesn’t belong is 31.
Why?
All the other numbers (12, 18, 24, 46) are even, while 31 is odd.
Also, 31 is the only prime number in the list.