並前往https://academy.snapask.com/zh-hk/post/%E9%8B%A4%E5%A4%A7Dee%E9%9D%9A%E7%89%8C%E6%A9%9F%E6%9C%83%E7%8E%87-%E6%A6%82%E7%8E%87%20Probability-%E6%8E%92%E5%88%97%E8%88%87%E7%B5%84%E5%90%88-Permutation-Combination-27f1cfca203e