In a series of numbers: 2, 4, 8, 16, ?, 64. What is the missing number?

B. 32

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

A. E

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

A. 16

What character should be placed in the blank: X, Y, Z, A, B, ?

A. C