I2.4 Determine the unit digit, $\delta$, of $\left(\left(\gamma^{\gamma}\right)^{\gamma}\right)^{\gamma}$.
$$
\left(\left(3^{3}\right)^{3}\right)^{3}=\left(3^{9}\right)^{3}=3^{27}
$$

The unit digit of $3,3^{2}, 3^{3}, 3^{4}$ are $3,9,7,1$ respectively. This pattern repeats for every multiples of 4 .
$$
\begin{array}{l}
27=6 \times 4+3 \\
\delta=7
\end{array}
$$