Problem 1

题目发布于 2001-10-06 翻译更新于 2020-10-22

Multiples of 3 and 5

If we list all the natural numbers below $10$ that are multiples of $3$ or $5$, we get $3$, $5$, $6$ and $9$. The sum of these multiples is $23$.

Find the sum of all the multiples of $3$ or $5$ below $1000$.

在小于$10$的自然数中，$3$或$5$的倍数有$3$、$5$、$6$和$9$，这些数之和是$23$。

求小于$1000$的自然数中所有$3$或$5$的倍数之和。