2 3 E 4 5 I 6 8

2 3 e 4 5 i 6 8

Answers:

2, 3, E, 4, 5, I, 6, 8, ?

2 + 3 = 5 = E (E is in 5th position in alphabets)

4 + 5 = 9 = I (I is in 9th position in alphabets)

6 + 8 = 14 = N (n is in 14th position in alphabets)

2, 3, E, 4, 5, I, 6, 8, N