The greatest common divisor of three positive integers 90ABC17, 79ABC and 491ABC4 is  ≥ 2, where each of A, B and C represents a different base 10 digit from 0 to 9.

Determine all possible triplet(s) (A,B,C) that satisfy the given conditions.

Note: While a solution is trivial with the aid of a computer program, show how to derive it without one.