What is the coolest letter in the alphabet?

When it's bad luck to meet a black cat?

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

John enters a small room. The Door Closes.
When the door opens, John is in a larger room.

Explain?

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

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

Can you divide the below-given shape into four equal and identical pieces?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

What have one eye but still cannot see?

In a chess board, the queen piece can move horizontally, vertically and diagonally freely. The picture represents the same.Can you place 8 queens on the board in a manner that none of the queens can attack each other?

In a boat, the father of a sailor's son is sitting with the son of the sailor. However, the sailor is not present on the boat.

Can this even be possible?