There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

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?

What is the next number in the series?

15 29 56 108 208 ?

How many times can you subtract the number 5 from 25?

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

There is something which is always coming but never arrives?

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

Move four matchsticks to the below square to form three squares?

Place the numbers from 1 to 9 in the circles in a manner that each side of the triangle sums up to 17.

There are two guys standing face to face in a room. On a wall, there is a clock. One of those is a prophet. He tells the other guy that he will be stabbed in the back in five minutes.

Shocked to hear that, the other guy stares at the clock. Just after the five minutes, he is stabbed on the back. Can you tell what happened?