Number Series - Verbal and Reasoning

Directions to SolveLook carefully for the pattern, and then choose which pair of numbers comes next.
Q1:

13 29 15 26 17 23 19

A 21 23

B 20 21

C 20 17

D 25 27

E 22 20

ANS:B - 20 21

Here, there are two alternating patterns, with every other number following a different pattern. The first pattern begins with 13 and adds 2 to each number to arrive at the next; the alternating pattern begins with 29 and subtracts 3 each time.