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

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

I throw two dice simultaneously.

What is the probability of getting a sum as 9 of the two numbers shown?

Which number should replace the question mark?

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.

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

In my garden, I have many trees but only one of them is the mango tree. In these mango trees, there are some mangoes(as expected).

But after a strong wind, there are neither mangoes on the tree nor on the ground. Explain?

Different lights make me strange by changing me into different sizes. What am I?

You need to move three matchsticks to form three squares. Can you do it?