$32 \cdot 1$ Among four numbers, the sums of every three numbers are $180, 197, 208, 222$. Then the largest of these four numbers is
(A) 77.
(B) 83.
(C) 89.
(D) 95.
(E) Uncertain.
(41st American High School Mathematics Examination, 1990)
[Solution] Let the four numbers be $x, y, z, w$. According to the problem, we have

So
$$
\begin{array}{c}
3(x+y+z+w)=180+197+208+222, \\
x+y+z+w=269,
\end{array}
$$

Then the largest number is $269-180=89$.
Therefore, the answer is (C).