There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

A bomb exploded in a room full of married couples and no one died. How?

Name a key which is hardest to turn.

How many times in a given day, minutes and hour clock comes in a straight line ?

How many triangles can you find in this given picture?

Remove two matchsticks to make the below equation correct.

A network of 20 x 10 squares is given to you.

Can you calculate how many unique squares and rectangles can be formed combining two or more individual squares ?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

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?

What is the coolest letter in the alphabet?