Two fathers and two sons went fishing one day. They were there the whole day and only caught 3 fish. One father said, that is enough for all of us, we will have one each. How can this be possible?

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.

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

Using eight eights and addition only, can you make 1000?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

Which digit occurred maximum times between the number 1 and 1000?

Whats the next number in the below number sequence pattern.

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