Capthan wrote:

If x and y are positive integers such that the product of x and y is prime, what is the units’ digit of 7x + 9y?

(1) 24 < y < 32

(2) x = 1

(A) Statement (1) ALONE is sufficient to answer the question, but statement (2) alone is not.

(B) Statement (2) ALONE is sufficient to answer the question, but statement (1) alone is not.

(C) Statements (1) and (2) TAKEN TOGETHER are sufficient to answer the question, but NEITHER statement ALONE is sufficient.

(D) EACH statement ALONE is sufficient to answer the question.

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

Product of two numbers prime means that one number is 1 and other number is prime number itself

Statement 1) tells that y is prime number since it is not 1 and prime number will be 29 in this case. Therefore 7x + 9y = 7*1 + 9*29. Sufficient

Statement 2) is not sufficient since it does not tell any way of finding value of y.

Answer is A)