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 is more useful when it is broken?

Move three sticks of the spiral below to form a square.

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

A professor thinks of two consecutive numbers between 1 and 10.
'A' knows the 1st number and 'B' knows the second number

A: I do not know your number.
B: Nor do I know your number.
A: Now I know.

What are the four solutions for this?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?