5 < 2n ≤ 20

5/2 < n < =10

n=3, 4, 5, 6, 7

5 < 2n ≤ 20   divide each term by 2

5/2 < n  ≤ 10

So.......the the possible values for n   exist in the interval  (5/2, 10 ]

We obviously can't write down ALL the possible values for n, since there are infinite values in the interval that would satisfy the inequality....!!!