Exercise :: Number Series  Type 4
 Number Series  Type 1
 Number Series  Type 2
 Number Series  Type 3
 Number Series  Type 4
Find the number that fits somewhere into the middle of the series. Some of the items involve both numbers and letters
11.  Look at this series: J14, L16, __, P20, R22, ... What number should fill the blank? 

Answer: Option B Explanation: In this series, the letters progress by 2, and the numbers increase by 2.

12.  Look at this series: 4, 7, 25, 10, __, 20, 16, 19, ... What number should fill the blank? 

Answer: Option A Explanation: Two series alternate here, with every third number following a different pattern. In the main series, 3 is added to each number to arrive at the next. In the alternating series, 5 is subtracted from each number to arrive at the next.

13.  Look at this series: XXIV, XX, __, XII, VIII, ... What number should fill the blank? 

Answer: Option C Explanation: This is a simple subtraction series; each number is 4 less than the previous number.

14.  Look at this series: 0.15, 0.3, ____, 1.2, 2.4, ... What number should fill the blank? 

Answer: Option C Explanation: This is a simple multiplication series. Each number is 2 times greater than the previous number.

15.  Look at this series: U32, V29, __, X23, Y20, ... What number should fill the blank? 

Answer: Option A Explanation: In this series, the letters progress by 1; the numbers decrease by 3.
