What is the 15th letter of the English alphabet?

A. O

In the series 'A, B, C, D, E, F, G, H, I, J, K', how many times does the letter 'E' occur?

A. 1

In the series A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, how many times does the letter 'E' appear?

A. 1

If 'Z' is the 26th letter, what is the 10th letter after 'Z' in a circular alphabet?

A. J

If the 5th letter is replaced by the 3rd letter, what is the new letter at the 5th position?

A. C