In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

What jumps when it walks and sits when it stands?

Buy me, smell me or deliver me, I do not change.

Who am I?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

what does the below math rebus puzzle mean?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

The host of a game show, offers the guest a choice of three doors. Behind one is a 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?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?