In this series, the letters progress by 1; the numbers decrease by 3.

This is a simple multiplication series. Each number is 2 times greater than the previous number.

This is a simple subtraction series; each number is 4 less than the previous number.

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.

 In this series, the letters progress by 2, and the numbers increase by 2.

This series alternates the addition of 4 with the subtraction of 3.

In this simple addition with repetition series, each number in the series repeats itself, and then increases by 12 to arrive at the next number.

This is a simple subtraction series in which a random number, 93, is interpolated as every third number. In the subtraction series, 10 is subtracted from each number to arrive at the next.

This is a multiplication series; each number is 3 times the previous number.

This is an alternating addition and subtraction series. Roman numbers alternate with Arabic numbers. In the Roman numeral pattern, each number decreases by 1. In the Arabic numeral pattern, each number increases by 1.

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.

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

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

This is an alternating division and addition series: First, divide by 2, and then add 8.

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

This is a simple addition series with repetition. It adds 3 to each number to arrive at the next, which is repeated before 3 is added again.

Two patterns alternate here. The first pattern begins with 10 and adds 2 to each number to arrive at the next; the alternating pattern begins with 34 and subtracts 3 each time.

 First number of a 2nd pair is the second number of the previous pair and difference between each pair number is 3. 1st Pair 17,14 2nd Pair 14,11 3rd pair 11,8 4th pair 8,5 5th pair 5,2

Here, there are two alternating patterns. The first begins with 17 and adds 2; the second begins with 32 and subtracts 3.

Here, there are two alternating patterns, one addition and one subtraction. The first starts with 2 and increases by 2; the second starts with 44 and decreases by 3.

Here, every third number follows a different pattern from the main series. In the main series, beginning with 16, 10 is added to each number to arrive at the next. In the alternating series, beginning with 56, 12 is added to each number to arrive at the next.

In this simple subtraction series, the numbers decrease by 3.

Two patterns alternate here, with every third number following the alternate pattern. In the main series(1st series) 4, 7, 10,13, 16 ..... beginning with 4, 3 is added to each number to arrive at the next. Secondary series (2nd series): 26, 20, ... beginning with 26, 6 is subtracted from each number to arrive at the next. Therefore Next two number is 19(from 1st series), 14(from 2nd series). 19,14

This is an alternating addition series that adds 5, then 2, then 5, and so on.

This is an alternating addition series with repetition, in which a random number, 66, is interpolated as every third number. The regular series adds 2, then 3, then 2, and so on, with 66 repeated after each "add 2" step.

This is an alternating repetition series. The number 32 alternates with a series in which each number decreases by 2.

This is a simple subtraction series, in which 4 is subtracted from each number to arrive at the next.

This is a simple subtraction series, in which 3 is subtracted from each number to arrive at the next.

In this simple addition with repetition series, each number in the series repeats itself, and then increases by 12 to arrive at the next number.

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.