Solution:

3 1 2 2 1 1
1 3 1 1 2 2 2 1

Read Line as one 1 => 1
Read Line 2 as two one => 2 1
Read Line 3 as one two and one one => 1 2 1 1
and so on.

Solution:

0 or 16

Explanation:
If you notice, then there is no pattern in this image between the numbers. The only thing is that the numbers are all jumbled up and continuous.

Therefore, the missing number can either be 0 or 16.

Solution:

Next in sequence is 13112221.

This series describes each number that came before it:
1 [One]
11 [One One]
21 [Two One(s)]
1211 [One Two and One One(s)]
111221 [One One, One Two, and Two One(s)]
312211 [Three One(s), Two Two(s), and One One]

The next number in the series is:
13112221 [One Three, One One, Two Two(s), Two One(s)]

Solution:

'2'

This single sequence in fact consists of two Series:
The first Series is 2-3-4-5-...
and
The second Series is 9-18-36-72-... .

Solution:

The missing number that fit in ? is 6.

The number in the middle of each triple is the same as the digits of either end's number when added together. 3+7=10=8+2 and so on.

Solution:

4

92 - 38 = 54
5 is given and 4 is missing

Solution:

100

list of consecutive numbers that does not contain a 'T' in the spelling

Solution:

29

Explanation:
If you look closely, you will find that the center number can be obtained by multiplying the largest numbers on the corners and subtracting the smallest number from it.

26 = 7 * 5 – 3^2

In the same manner, every other figure follows. Thus the missing number:
9 * 5 – 4^2
= 45 – 16
= 29

Solution:

L8

Explanation:
To know why, just read the number series upside down and you will find that the numbers are 91, 90, 89, 88, __, 86
So L8 when read upside down reads as 87.

Solution:

4

6*3 equals 18
7*9 equals 63
6*4 equals 24
7*6 equals 42, ? should be replaced by 4.