13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

As we know that white starts the game of chess. Can you find the scenario shown in the picture below is possible when all the white pieces are at the original place while the black pawn is not as in the below picture?

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

Suppose you are a girl candidate and sitting in an interview. Suddenly the interviewer asks you, 'What if one morning you wake up and find out that you are pregnant?

How will you reply to such a question?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

A horse was tied to a rope 5 meters long and the horses food was 15 meters away from the horse. How did the horse reach the food?

What breaks yet never falls, and what falls yet never breaks?