Identify the missing number in the series: 5, 10, 20, 40, ?, 160

A. 80

Identify the missing number in the series: 5, 10, 20, 40, ?, 160

C. 80

What is the missing number in the series: 2, 4, 8, 16, ?, 64?

A. 32

What letter should come next in the series: z, x, v, t, ?

A. S

Identify the missing letter in the series: Z, X, V, T, ?

D. P