$2 \cdot 9$ A town's population increased by 1200 people, and then this new population decreased by $11 \%$. The current number of people in the town is 32 fewer than before the increase of 1200 people. What was the original population?
(A) 1200.
(B) 11200.
(C) 9968.
(D) 10000.
(E) None of these.
(25th American High School Mathematics Examination, 1974)
［Solution］Let $x$ be the original population, then according to the problem, we have

Solving, we get
$$
\begin{array}{c}
x+1200-0.11(x+1200)=x-32, \\
x=10000 .
\end{array}
$$

Therefore, the answer is $(D)$.