1. **State the problem:** Given the input-output pairs of a function: input $3,6,8,n$ and output $6,12,16,\square$, find the output when the input is $n$. 2. **Analyze the pattern:** Look at the given inputs and outputs: - When input is $3$, output is $6$. - When input is $6$, output is $12$. - When input is $8$, output is $16$. 3. **Identify the rule:** Notice that each output is twice the input: $$\text{output} = 2 \times \text{input}$$ 4. **Apply the rule to input $n$:** $$\text{output} = 2 \times n = 2n$$ 5. **Final answer:** The output when the input is $n$ is: $$\boxed{2n}$$ This means the function doubles the input value to get the output.