3. If a number is added to the sum of its digits, the result is 328. Find this number.
# 3. Answer: 317

Let's denote the digits of the desired number as a, b, c, and their sum as s. Then abc $+\mathrm{s}=328$. Since $s$ is the sum of three single-digit numbers, s does not exceed 27, so a $=3$. At the same time, b cannot be zero, because otherwise the maximum value of s would be $3+0+9=12$. If $\mathrm{b}=1$, then $31 \mathrm{c}+(4+\mathrm{c})=328$, c $=7$. If $\mathrm{b}=2$, then $32 \mathrm{c}+(5+\mathrm{c})$ $=328$, there are no integer solutions here.

Comment on checking.

The digits of the number are correctly and justifiedly found: 3 points.