Need help with DS

anniebag

If a and b are intergers, is b even?
1) 3a+4b is even
2) 3a+5b is even

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient

Thanks~

zmaggie

条件 1：4b为偶数，证明 a 是偶数， 但无法确定b
条件2：a or b 同时为奇数，或同时为偶数。

答案应该 为 C。

anniebag

I agree~ I chose c too. But OA is E .   I don't know why