# Aidan is 18 years older than Summer. If he is 46 now, when was he twice her age?

Let Summer's age be $n$. Then Aidan's age is $n + 18$. We're trying to find where $n + 18 = 2 n$, which can easily be solved for $n = 18$.
So when Summer was $18$, Aidan was twice her age, $36$. If he is $46$, then he was twice her age $10$ years ago.