Identify the missing character in the series 1, 4, 9, ?, 25, 36.

A. 16

In the pattern: X, Y, Z, A, ?, C. What character is missing?

A. B

Identify the missing character in the series 1, 4, 9, ?, 25.

A. 16

In the sequence: M, N, O, ?, Q, R. What letter is missing?

A. P

In the sequence A, B, C, ?, E, F, what character should replace the question mark?

A. D