2013-II-10

$\begin{array}{cl}
= & \$80~080 \div (1+30\%) \\
= & \$61~600
\end{array}$

虧損汽車的成本

$\begin{array}{cl}
= & \$80~080\div (1-30\%) \\
= & \$114~400
\end{array}$

所以，總收支

$\begin{array}{cl}
= & 2\times\$80~080 -(\$61~600+\$114~400) \\
= & -\$15~840
\end{array}$

所以完成該兩項交易後，素珊虧蝕 $\$15~840$。