If X is an odd integer and Y is an even integer, which of the following statements is (are) always true? 1. X+Y is odd 2. XY is odd 3. X+2y is even
A
1 only
B
2 and 3 only
C
1 and 3 only
D
3 only
Correct Answer: 1 only
1. Addition of odd and even integers yields odd intgers. Example: 4 + 3 = 7. So, statement 1 is true. 2. Multiplication of odd and even integers yields even integers. Example: 4x3 = 12. So, statement 2 is false. 3. 2y is odd and x is odd. So, x + 2y is odd. Therefore, statement 3 is false.