For each of these patterns, a certain number is added each time.
9, _, 27, _, _, 54.
For this one, The first term and the third term have a difference of 18. In order to find the second term, we must divide this number by 2.
18/2 = 9
We find that it is increasing 9 each term.
9, 18, 27, 36, 45, 54.
3, 6, 9, _, _, _.
From the first term to the second, the difference is 3, which is the same as the second to third.
Therefore we find that it is adding 3 each time.
3, 6, 9, 12, 15, 18.
0, 22, _, _.
From the first term to the second, it is adding 22.
Therefore the pattern should look like:
0, 22, 44, 66.