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