Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Can you complete the sequence puzzle?

AR TA GE CA LE VI LI _

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.

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

A very interesting trivia question for all.

Why do men's shirts have their buttons on the right side and women's have buttons on the left-hand side?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?