It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

What is common among 11, 69, and 88?

I know a ten-letter word in the English language which can be typed using only the top rows of the computer keyboard.

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

On a bright sunny day, two fathers took their son fishing in the lake. Each man and son were able to catch one fish. When they returned to their camp, there were only three fishes in the basket. What happened?

PS: None of the fish were eaten, lost, or thrown back.

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 you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

What came first, the chicken or the egg?

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?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?