Direction In each series, look for the degree and direction of change between the numbers. In other words, do the numbers increase or decrease, and by how much-
26.

2 3 4 5 6 4 8
A. 9 10
 B. 4 8
C. 10 4
 D. 9 4
Answer and Explanation
Answer: D

Explanation: This is an alternating addition series with a random number, 4, interpolated as every third number. In the main series, 1 is added, then 2 is added, then 1, then 2, and so on.




27.

17 17 34 20 20 31 23
A. 26 23
 B. 34 20
C. 23 33
 D. 27 28
Answer and Explanation
Answer: E

Explanation: This is an alternating subtraction series with repetition. There are two different patterns here. In the first, a number repeats itself; then 3 is added to that number to arrive at the next number, which also repeats. This gives the series 17, 17, 20, 20, 23, and so on. Every third number follows a second pattern, in which 3 is subtracted from each number to arrive at the next: 34, 31, 28.




28.

6 20 8 14 10 8 12
A. 14 10
 B. 2 18
C. 4 12
 D. 2 14
Answer and Explanation
Answer: D

Explanation: This is an alternating addition and subtraction series. In the first pattern, 2 is added to each number to arrive at the next; in the alternate pattern, 6 is subtracted from each number to arrive at the next.




29.

21 25 18 29 33 18
A. 43 18
 B. 41 44
C. 37 18
 D. 37 41
Answer and Explanation
Answer: D

Explanation: This is a simple addition series with a random number, 18, interpolated as every third number. In the series, 4 is added to each number except 18, to arrive at the next number.




30.

75 65 85 55 45 85 35
A. 25 15
 B. 25 85
C. 35 25
 D. 85 35
Answer and Explanation
Answer: B

Explanation: This is a simple subtraction series in which a random number, 85, is interpolated as every third number. In the subtraction series, 10 is subtracted from each number to arrive at the next.