This riddles consist of 3 Numbers with 4 Digits each and you have to find the 4th one.
How to solve: Lets say the first number is ABCD, then all you need to do is check the 2nd number, if it is BCDA, the solution is DABC. If it is DABC the solution is BCDA.
Example: 1234 - 2341 - 3412 - ???? (4123)
You get 5 numbers and have to find the 5th one. This ones are a bit trickier, but they can be solved by an easy subtraction / addition inverse pyramid.
How to solve: Basically what you do is write down the numbers with enough space between them, and write the difference between following numbers between them. Usually you can see that way how the series is constructed.
Example: 17 - 33 - 65 - 129 - ?
17 33 65 129 ? (257)
16 32 64 ? (128)
16 32 ? (64)
You can see that the difference just needs to be multiplied by two in that sequences. The other ones were similar like that, although there might be a case where you reach numbers that are the same, so instead of 16 - 32, you reach 16 - 16, then you can easily identify the next one as 16, so then all you need to do is add that up.
Note: There is another type of sequence. Should the differences be of no use, you will have to divide the numbers through the next one to understand the construction of the sequence.
Example: 5040 - 720 - 120 - 24
5040 720 120 24 ?
7 6 5 ?