What number should replace the question mark in the series: 2, 4, 8, 16, ?

C. 32

What is the next letter in the series: A, C, E, G, ?

B. H

What is the next letter in the series: A, C, E, G, ?

B. H

What number should come next in the series: 10, 20, 30, 40, ?

B. 50

What is the next letter in the series: M, O, Q, S, ?

B. T