8. Calculate the answer

If \(X\) \(=\) \(\{x: x\) is a multiple of \(2\), \(n \in \mathbb{N}\) and \(n \le 20\}\), \(Y\) \(=\) \(\{x: x\) is a multiple of \(3\), \(n \in \mathbb{N}\) and \(n \le 20\}\) and \(Z\) \(=\) \(\{x: x\) is a multiple of \(6\), \(n \in \mathbb{N}\) and \(n \le 20\}\), then find \( X\cup (Y \cap Z)\).

 

\(X \cup (Y \cap Z)\) \(=\) \(\{\)\(\}\).

 

[Note: Enter the numbers in ascending order, also insert a comma to separate the numbers]