This is an alternating subtraction series with the interpolation of a random number, 5, as every third number.

Correct Option: A

This is an alternating subtraction series with the interpolation of a random number, 5, as every third number. In the subtraction series, 3 is subtracted, then 4, then 3, and so on.

This is a simple addition series,

Correct Option: B

This is a simple addition series, which begins with 2 and adds 6.

In this alternating repetition series, a random number,

Correct Option: A

In this alternating repetition series, a random number, 33, is interpolated every third number into a simple addition series, in which each number increases by 2.

This is a simple addition series with a random number, 18, interpolated as every third number.

Correct Option: D

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.

This is a simple subtraction with repetition series. It begins with 20,

Correct Option: E

This is a simple subtraction with repetition series. It begins with 20, which is repeated, then 3 is subtracted, resulting in 17, which is repeated, and so on.