A and B are integers. The expression (A+1)(B+1) is even. What can be said about A and B?
Options:
(A) They are both even numbers.
(B) At least one of them is even
(C) At least one of them is odd.
(D) They are both odd.
(E) Nothing can be said surly on A and B Now, let's think a bit. Some random thoughts:
Odd x Odd = Odd
Odd x Even = Even
Even x Even = Even
To fulfill condition Either (A+1) or (B+1) needs to be Even
So either A or B needs to be odd
Or At Least one of them is odd.
The final answer: (C).