In the sequence 2, 4, 8, 16, ?, 64, what is the missing number?

B. 32

Find the missing character in the series: M, N, O, ?, Q, R.

A. P

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

A. 16

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

A. A

In a sequence of letters: A, C, E, G, ?, K. What is the missing letter?

B. H