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-
61.

Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?
A. A16
 B. G4
C. E4
 D. E3
Answer and Explanation
Answer: C

Explanation: The letters decrease by 1; the numbers are multiplied by 2.




62.

Look at this series: 664, 332, 340, 170, ____, 89, ... What number should fill the blank?
A. 85
 B. 97
C. 109
 D. 178
Answer and Explanation
Answer: D

Explanation: This is an alterna
63.

Look at this series: V, VIII, XI, XIV, __, XX, ... What number should fill the blank?
A. IX
 B. XXIII
C. XV
 D. XVII
Answer and Explanation
Answer: D

Explanation: This is a simple addition series; each number is 3 more than the previous number.




64.

Look at this series: 70, 71, 76, __, 81, 86, 70, 91, ... What number should fill the blank?
A. 70
 B. 71
C. 80
 D. 96
Answer and Explanation
Answer: A

Explanation: In this series, 5 is added to the previous number; the number 70 is inserted as every third number.




65.

Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?
A. 8
 B. 14
C. 43
 D. 44
Answer and Explanation
Answer: B

Explanation: This is a simple alternating addition and subtraction series. The first series begins with 8 and adds 3; the second begins with 43 and subtracts 2.