3.13 A three-digit number ends with the digit 2. If it is moved to the beginning of the number, the resulting number will be 18 more than the original. Find the original number.
3.13 Let the desired three-digit number be of the form $100x + 10y + 2$; then after moving the digit 2, it will take the form

$200 + 10x + y$.

By the condition,

$200 + 10x + y - (100x + 10y + 2) = 18$

from which $10x + y = 20$. Substituting this expression into (1), we get $200 + 20 = 220$. Thus, the original three-digit number is 202.

Answer: 202.