In the first example, Sasha has five ways to invite residents to solve tasks:

\begin{itemize}
\item only with the resident on floor $1$;
\item with residents on floors $1$ and $2$;
\item with residents on floors $1$ and $3$;
\item with residents on floors $1$, $2$, and $3$;
\item with residents on floors $2$ and $3$;
\end{itemize}

Sasha cannot invite the resident from floor $2$ alone to solve the task, as then the highest floor where all residents willing to solve the task could gather would be floor $2$, while Sasha wants to solve the task on floor $1$.

In the second example, two different suitable ways to invite residents to solve tasks could be as follows:
\begin{itemize}
\item Invite residents from floors $2$ and $6$ to solve the first task, and the resident from floor $5$ to solve the second task.
\item Invite the resident from floor $2$ to solve the first task, and residents from floors $5$ and $6$ to solve the second task.
\end{itemize}