39
21
are you sure it is not1 2 3 6 8 7 14 16because that sequence doubles for the first one, then adds two for the next number, then subtracts one for the third, then repeats. So the next number is 15.
A number sequence is not a question. So there can be no "answer".
15 since you multiply by 3 then subtract 3 in sequence
15!
15
23
15
17?
The next number in the sequence 3-15-6-30-21 is -207.
The next number could be 26 The next number could be 12 - - - - - - - - - The next number that is in the sequence is 12.
It is 129.
21
10,20,30,20
There really is no way of telling, but my guess is 22.
.75
12-13-15 etc.... The sequence is add 1 then add 2