What does this rebus puzzle means ?

Can you solve the maths in the below-given picture equation?

There are six people in a family namely M, N, O, P, Q and R.

R and O are brother and sister.

N is the brother of Q's husband.
P is the father of M and grandfather of R.

How many male members are in the family?

A man was driving a black truck. His lights were not on. The moon was not out. A lady was crossing the street. How did the man see her?

In case you were starting to feel confident, this one was meant for third graders in Vietnam. The answer is 66, but we don't blame you for scratching your head about how they got there.

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What is the centre of gravity?

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.

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

What's the best place to go shopping in the ocean?