Ages

Age problems are solved by assigning variables to unknown ages and setting up equations based on the information given. The key property is that the difference between two people's ages remains constant over time. If $x$ is the current age of one person and $y$ is the current age of another, then $x - y$ is always the same, even after $n$ years.

Important properties

• The age difference between two people does not change over time.

• Ages in the past or future can be expressed as current age plus or minus years.

• Setting up equations based on the information given allows you to solve for unknown ages.