What is always in front of you but can’t be seen?

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.

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Complete the table series riddle by finding the number that can replace "??".

When monkey rotate the gear, which mark will be hit 1 or 2 ?

Can you move 2 matchsticks to form four equal sized squares.

You have 1023 apples and 10 bags. You have to distribute these apples in these 10 bags in any way you choose. But when I ask for a certain number of apples you have to give them in terms of bags without transferring the apples from other bags. How do you distribute the apples?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

Chef Andrea has to light the kitchen stoves to open her restaurant for the day. There are three stoves in the kitchen: A glass stove, a brick stove, and a wood stove. She only has one match. Which does she light up first?