Q11:

Is the sum of the integers x and y a prime number?

(1) x is an even prime number.

(2) y is a prime number between 10 and 20.

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.

选e吧，x is an even prime number.所以x是2，这个不充分，2+13=15 2+17=19

y is a prime number between 10 and 20.也不充分，2+13=15 2+17=19

二者合起来，上面的例子也可以反驳