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?

Find the next number in the series below

21 32 54 87 131 ?

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)

Jack have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the colour of the socks. How many of the socks did he want to take to match one pair

A little girl goes to the store and buys one dozen eggs. As she is going home, all but three break. How many eggs are left unbroken?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?