Question 363479
Let us say the two numbers are 2m + 1 (odd) and 2n (even) where m and n are integers irrespective of being odd or even.


Halfway between them is (2m + 1 + 2n)/2 = (m + n) + ½


So the even-odd number X must be of the form N + ½ where N can be any integer.


Therefore

2X is an integer (odd)

2X cannot be an even-odd number since 2X is an integer and not of the form N + ½

X cannot be halfway between two even integers since half way between two even integers is an integer too and X is of the form N + ½


Therefore only the first one is correct which means the answer is A.