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\begin{enumerate}

    \item $Z = \{n: n \text{ is a whole number}\}$

    \item $Z^+ = \{n: n \text{ is a positive whole number}\} $

    \item $P(Z) = \{S\; : \; S \subset Z\}$

    \item $Q = \{a/b\; : \; a, b \in Z, b\ne 0\}$

    \item $R$ (decimals)

\end{enumerate}