Identify the missing term in the series: 3, 6, 11, 18, ?

A. 25

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

B. 50

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

A. 32

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

C. 80

What number should replace the question mark in the series: 1, 1, 2, 3, 5, ?

B. 8