Answers:

(i)

If we read the complete sentence it becomes x and the letter x comes before ‘e’ in the English alphabet.

Thus, the letters before the letter ‘e’ are a,b,c,d.

∴ Roster form = {a,b,c,d}

(ii)

x ∈ N (x – natural number)

Then,

x² < 25

x < ±5

If x is a natural number then x < 5.

All numbers that are less than 5 are 1,2,3,4.

∴ Roster form = {1,2,3,4}.