\[ x + 2y = 8 \quad \text{and} \quad 2x + 4y = 16. \]
Step 1: Analyze the system of equations.
The first equation is:
\[ x + 2y = 8. \]
The second equation is:
\[ 2x + 4y = 16. \]
Step 2: Check if the equations are consistent or dependent.
Multiply the first equation by 2:
\[ 2(x + 2y) = 2(8) \implies 2x + 4y = 16. \]
This shows that the second equation is simply a multiple of the first equation. Hence, the two equations represent the same line.
Step 3: Determine the number of solutions.
Since the two equations represent the same line, they have infinitely many solutions (every point on the line satisfies both equations).
Final Answer: The number of solutions is \( \mathbf{\text{infinitely many}} \), which corresponds to option \( \mathbf{(4)} \).