Solve the following series:
AZ, GT, MN, __, YB

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

Rearrange the letters in "new door" to make one word.

If a zookeeper had 100 pairs of animals in her zoo, and two pairs of babies are born for each one of the original animals, then (sadly) 23 animals don’t survive, how many animals do you have left in total?

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?

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

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

Give it food and it will live; give it water and it will die.

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

A container contains 100 eggs. They can be either fresh or rotten. What is sure is the fact that there is at least one fresh egg in that container.

If you are asked to pick two eggs randomly from the container, at least one of them will be rotten.

Can you calculate how many eggs in that container are fresh?