Question

If x is a prime number,then x+1 is not a prime number

Answer 1

Always, except if x=2

Explanation:

Always, except if x=2, because 2+1=3; and 3 is also a prime number.

Answer 2

false, 2 is a prime number and 2+1 is 3
That is the only counter example.
This is only true for primes greater than 2