A blonde put eyeliner on her head. Why?

Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

10+10 and 11+11 can give you the same answer.

Explain how?

Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

What can you deduce from the following BrainBat?

CRY
LMKI

Find the next number in the series below

21 32 54 87 131 ?

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

What does below chemistry rebus means?

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

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.