Ans: (a) $\$576$ (b) Christine
- The daily wage of Ada
$\begin{array}{cl}
= & \$480\times (1+20\%) \\
= & \$576
\end{array}$ - The daily wage of Christine
$\begin{array}{cl}
= & \$480\div(1-20\%) \\
= & \$600
\end{array}$$\because \$600 > \$576 > \$480$,
$\therefore $ Christine has the highest daily wage.
