bigfernhead wrote:

X and Y are prime integers. What is |X-Y|?

X + Y is a prime integer

Both X and Y are less than 5

I thought this one was tricky.

The original statement says that X & Y are prime integers.

Statement 1 says that X+Y is a prime integer. This statement is not sufficient because 2+3=5 (satisfies the statement) also 5+2=7 (satisfies the statement). There is no definite answer using this statement. So, its insufficient.

Statement 2 says that X & Y are less than 5. The only prime numbers less than 5 are 2 & 3. So, the define answer for |X-Y| = 1. So, its sufficient.

Answer is

B