46. a and b are integers, is b even?
(1) 3a+4b is even.
(2) 4a+6b is even.
I think its E
Odd integer + Even integer = Odd integer
Even integer + Even integer = Even integer
For 1), we need both an even integer for both 3a and 4b. 3a can only be even when a is an even integer. 4b can be an even integer when b is odd or even. So 1) alone cannot give us an anwer whenther b is even. So eliminate D & A.
For 2), we know 4a is an even number with either a is odd or even. Same logic applys to 6b, as an odd b or even b will give 6b an even number. So 2) alone is not sufficient to answer the question. We can eliminate B.
1) + 2) together cannot help us answer the question, so C is gone too, and this left us with E as the correct answer.