complete the pattern

Question

12,18,15,21,18,?,?,?,?,?,?,
13,26,18,36,23,?,?,?,?,?,?,?,
44,54,47,57,50,?,?,?,?,?,?,?,
5,14,15,24,25,?,?,?,?,?,?,?,?

Answer 1

12,18,15,21,18,24,21,27,24,30,27(+6,-3)

Answer 2

5,14,15,24,25,34,35,44,45,54,55 (+9,+1)

Answer 3

12,18,15,21,18,?,?,?,?,?,?,
12 + 6 = 18
18 - 3 = 15
15 + 6 = 21
21 - 3 = 18
What do you think the next numbers are?

13,26,18,36,23,?,?,?,
13 * 2 = 26
13 + 5 = 18
18 * 2 = 36
18 + 5 = 23
What do you think the next numbers are?

Can you see a pattern in the next two groups of numbers? If you post your answers, we'll be glad to check them for you.

Answer 4

hints NOT ANSWERS !!!
+6 -3 + 6 - 3 ....

*2 + (back 2+5) *2 + (back2 +5)

+10 -7 +10 -7

9 1 1 9 1 1 9 1 1 ....

Answer 5

12,18,15,21,18,24,21,27,24,30,27,34
13,26,18,36,23,36,28,41,33,46,38,51
44,54,47,57,50,60,63,73,66,76,69,79,72,
15,14,15,24,25,34,35,44,45,54,55