Move four matchsticks to the below square to form three squares?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

I am an odd number. Take away a letter and I become even. What number am I?

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

O T T F F S S ?

If a wheel has 54 spokes, how many spaces are there between the spokes?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

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.

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.