1.None of they three people are not students.
2.All of they three ones are not students.或者Not all of they three ones are students.
3.None of they two people are students.
4.Both of they two people are students.或者Not both of they two ones are students.
5.Tom and Jack are students/are not students.
6.Tom ,Jack and Alice are students/are not students.
5和6句这样写没问题，不过你要看全部否定和全部肯定的用法，可以写成
5.Both of Tom and Jack are students/are not students.
6.All of Tom ,Jack and Alice are students/are not students.
也就是说两人的话用both三人及三人以上用all