If 3 is the first term in the sequence, 9=3+6 (second term), 9+6=15 (third term), and so on.
Therefore, the sixth term is
[tex]\begin{gathered} \text{sixth term}\to3+6+6+6+6+6=3+5\cdot6=3+30=33 \\ \Rightarrow\text{sixth term}\to33 \end{gathered}[/tex]
The missing value is 5. The rest of the gaps are correct.
