6) Consider the three-digit natural numbers $n$ that satisfy the following property: the digits of $n$ are three consecutive numbers in any order (example 645). How many of these numbers are prime?
(A) None

| (B) 1 | (C) 2 |
| :--- | :--- |

(D) more than 2, but less than 10
(E) more than 10.
6) The answer is (A)

The sum of three consecutive numbers is always a multiple of three, so none of the numbers considered is prime since they all have the factor three according to the well-known divisibility rule.