In the pattern: X, Y, Z, ?, B, what character is missing?

A. A

In the series 1, 4, 9, ?, 25, what number should replace the question mark?

A. 16

What character should replace the question mark in the pattern X, Y, Z, A, B, ?

A. C

In a sequence of letters: A, C, E, G, ?, K, M, O, what is the missing letter?

B. H

In the series X, Y, ?, A, B, what letter should replace the question mark?

A. Z