What number completes the series:
5, 8 13, 20, ____?
Show answer & explanation
Correct answer: C
Explanation
5, 8, 13, 20, ?
8 − 5 = 3
13 − 8 = 5
20 − 13 = 7
The differences are 3, 5, 7, respectively, i.e., consecutive odd numbers.
The next difference will be 9.
20 + 9 = 29
Correct answer: 29