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?

What makes this number unique: 8,549,176,320?

What has lots of eyes, but can’t see?

I am quite hot but become too cold if you remove the first two letters. What am I?

One absent-minded ancient philosopher forgot to wind up his only clock in the house. He had no radio, TV, telephone, internet, or any other means for telling time. So he travelled on foot to his friend's place a few miles down the straight desert road. He stayed at his friend's house for the night and when he came back home, he knew how to set his clock. How did he know?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

Can you identify if it's a murder or a suicide ?

The centre of the third figure is empty. What digit should fit inside?

What will you call your mother's brother's brother-in-law?