Subtract two, multiply by two, subtract one. :)
14
12-13-15 etc.... The sequence is add 1 then add 2
31
The series appears to alternate between two patterns: one sequence (3, 6, 9) increases by 3, while the other (4, 7, 10) increases by 3 as well. The next number after 10, following the second sequence, would be 13. Therefore, the next number in the series is 13.
11, -10, 9
20
11
11.
11
21
15
22
What number best completes the sequence 1 1/2 5 10 1/2 18
10,20,30,20
The next number in the sequence is 27.
The sequence appears to alternate between adding and subtracting numbers. The pattern seems to be +11, -7, +5, -2, +6. Following this pattern, the next number in the sequence would be +3 from the previous number, which would be 21.
14