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.

If 21x = 79x, what is the value of x?

I know a country, If you remove the last alphabet of its name, it will become a part of your body. Do you name it?

Can you replace the X (both small and big x) with the numbers between 1 to 19 such that all the rows of 3 numbers between X (big x) sum to 23?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

John said, "If yesterday was tomorrow, today would be Friday."

When did John make this statement?

Can you count the number of blocks in the picture below?

A train leaves from point A for point B at 80 mph. After half an hour, another train leaves from point B for point A at 60 mph.

Which of the trains will be farther from point A when they meet ?

People put me on the table and cut me but do not eat me. What am I?

What Does this text mean:

important=important