\[\boxed{\mathbf{10}\mathbf{.}}\]
\[1)\ 3,\ 6,\ 9,\ 12,\ 15,\ 18,\ 21,\ 24,\ 27,\ 30.\]
\[2)\ 4,\ 8,\ 12,\ 16,\ 20,\ 24,\ 28,\ 32,\ 36,\ \]
\[40.\]