Logical Reasoning - Number Series

Exercise : Number Series - Type 4
Directions to Solve
Find the number that fits somewhere into the middle of the series. Some of the items involve both numbers and letters

1.
Look at this series: F2, __, D8, C16, B32, ... What number should fill the blank?
A16
G4
E4
E3
Answer: Option
Explanation:
The letters decrease by 1; the numbers are multiplied by 2.

2.
Look at this series: 664, 332, 340, 170, ____, 89, ... What number should fill the blank?
85
97
109
178
Answer: Option
Explanation:
This is an alternating division and addition series: First, divide by 2, and then add 8.

3.
Look at this series: V, VIII, XI, XIV, __, XX, ... What number should fill the blank?
IX
XXIII
XV
XVII
Answer: Option
Explanation:
This is a simple addition series; each number is 3 more than the previous number.

4.
Look at this series: 70, 71, 76, __, 81, 86, 70, 91, ... What number should fill the blank?
70
71
80
96
Answer: Option
Explanation:
In this series, 5 is added to the previous number; the number 70 is inserted as every third number.

5.
Look at this series: 8, 43, 11, 41, __, 39, 17, ... What number should fill in the blank?
8
14
43
44
Answer: Option
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.