A sequence has 2, 4, 6, 8, 10, 12, 14. The rule for the sequence is;

What is the next number in this sequence 4, 8, 12, ......, 20?

The rule for this sequence 18, 15, 12, 9, 6, 3, 0 is;

12, ..........., 32, 42, 52. The missing number is;

103, 107, 111, 115, 119, 123. The rule for this sequence is;