What has to be broken before you can use it?

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 four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?

Can you spot the hidden girl in the picture below?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

John was born on March 5, 1970, in Delhi, India. Jacob was born 25 days before John. The year when they took birth, Republic Day fell on Monday.

Can you find out on what day was Jacob born?

How can you leave a room with two legs and return with six legs?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?