GWD18-Q36

gmataren

Q36:  

If x and y are integers, is y an even integer?  A

      (1)     2y – x = x² – y²

(2)     x is an odd integer.

                  

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.

ecsniffers

2y – x = x² – y² =>2y=x²+x – y²  =>2y=x(x+1)- y²      

Since 2y is even, x(x+1) --the product of 2 consecutive integer-- is even, then y²  must be even, so y is even.