In the sequence 2, 4, 8, ?, 32, 64, what is the missing number?

A. 16

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

A. W

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

B. 32

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

B. H

In the pattern 5, 10, 15, ?, 25, what number is missing?

A. 20