If the sequence is A, C, E, G, what is the next letter?

B. H

If Z is to Y as X is to what letter?

A. W

Identify the next term in the series: Z, Y, X, W, ?

A. V

In the sequence 5, 10, 20, 40, what is the next number?

C. 80

Which of the following does NOT belong to the group: 1, 4, 9, 16, 25?

D. 30