Let's use S to represent Sydney's age. According to the problem, Devaughn is 11 years younger than Sydney, so his age can be represented as S - 11. We also know that the sum of their ages is 73, so we can write an equation:
S + (S - 11) = 73
Simplifying this equation, we get:
2S - 11 = 73
Adding 11 to both sides, we get:
2S = 84
Dividing both sides by 2, we get:
S = 42
Therefore, Sydney is 42 years old.