There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

A chicken farmer has figured out that a hen and a half can lay an egg and a half in a day and a half. How many hens does the farmer need to produce one dozen eggs in six days?

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 prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?

What is so fragile that saying its name breaks it?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

what does the below math rebus puzzle mean?

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

What has many keys but can’t open a single lock?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?