Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Why Aeroplane windows are round?

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

A cat had three kittens: Snophy, Topsy and Jorden. What was the mother's name?

Can you find out who is the kidnapper in below Picture and why, Explain ?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

81 x 9 = 801. What must you do to make the this equation true?

Forwards I am heavy, backward I am not. What am I?

An octopus has 8 legs. A hippogriff has 6 legs and 2 pairs of wings. A sphinx has 6 legs and one pair of wings. Now we have all 3 kinds and a total of 18 insects in a cage. We have a total of 118 legs and 20 pairs of wings. How many insects do we have of each kind?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?