Ans: (a) $\$920$ (b) $\$600$
- Let $\$x$ be the marked price of the wallet.
$\begin{array}{rcl}
x \times (1 – 25\%) & = & 690 \\
x & = & 920
\end{array}$Therefore, the marked price of the wallet is $\$920$.
- Let $\$y$ be the cost of the wallet.
$\begin{array}{rcl}
y \times (1 + 15\%) & = & 690 \\
y & = & 600
\end{array}$Therefore, the cost of the wallet is $\$600$.
