Final answer:
To find Sydney's age, we can set up an equation by representing Sydney's age as x, and Devaughn's age as three times x. Solving the equation x + 3x = 68 will give us Sydney's age as 17.
Step-by-step explanation:
To solve this problem, let's represent Sydney's age as x. Since Devaughn's age is three times Sydney's age, we can represent Devaughn's age as 3x. According to the given information, the sum of their ages is 68, so we can write the equation x + 3x = 68. This simplifies to 4x = 68. Dividing both sides of the equation by 4, we find that x = 17. Therefore, Sydney's age is 17.