Find the next number in the series below

21 32 54 87 131 ?

what does the below rebus mean?

Can you find a five letter word that is left with only two letters if one is removed?

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.

Luis Garavito killed Density x Volume.

Who is Luis Garavito ?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

What four weights can be used to balance from 1 to 30 pounds?

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

When did John make this statement?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?