Can you find the thief by just looking at the picture below?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

What has one letter and starts with an E?

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

What is next number in the pattern below:

131 517 192 123 ?

What can you deduce from the following BrainBat?

CRY
LMKI

The more it dries, the wetter it becomes. Can you tell what it is?