$32 \cdot 24$ Among the natural numbers from 1 to 1992, the number of numbers that are multiples of 3, but not multiples of 2 or 5, is
(A) 664.
(B) 465.
(C) 266.
(D) 200.
(9th "Jinyun Cup" Junior High School Mathematics Invitational, 1992)
[Solution] Among the natural numbers from $1 \sim 1992$, the numbers divisible by 3 are $\left[\frac{1992}{3}\right]=664$, the numbers divisible by both 3 and 2 are $\left[\frac{1992}{3 \cdot 2}\right]=332$; the numbers divisible by both 3 and 5 are $\left[\frac{1992}{3 \cdot 5}\right]$
$=132$; the numbers divisible by 3, 2, and 5 simultaneously are $\left[\frac{1992}{5 \cdot 3 \cdot 2}\right]=66$. Here $[a]$ represents the greatest integer not exceeding $x$.
Therefore, the numbers from 1 to 1992 that are multiples of 3 but not multiples of 2 or 5 are
$$
664-332-132+66=266 \text{ (numbers). }
$$

Hence, the answer is $(C)$.