Label the balls A, B and C. There are only three possible results when only one ball is drawn: A, B or C; when two balls are drawn there are only three combinations: AB, AC, BC, but either ball could be drawn first, so we also have BA, CA, CB, giving 6 permutations altogether; there are 6 permutations when drawing three balls: ABC, ACB, BAC, BCA, CAB, CBA.