In 2000, Margaret was twice Charlie's age. In 2007, she was $7$ years older than Charlie. How old is Charlie in 2011?

Let \(m\) be the age of Margaret in 2000, and let \(c \) be the age of Charlie in 2000.

 

From the first sentence, we know that \(2c = m\)

 

From the second sentence, we know that \(m + 7 = c + 7 + 7\), meaning \(m = c + 7\), so \(c = 7\) and \(m = 14\)

 

So, in 2011, Charlie was \(7 + 11 = \color{brown}\boxed{18}\)