John named his first son Alpha, second Beta, third Charlie and fourth Delta. What is the fifth son's name?

I know a nine-letter word having only one vowel.
Do you ?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

Why do people go to bed?

In a university, a professor gave a set of three problems to the three brilliant students of his class. See the image for the questions.

There are two words one resembles the "state of rest" and the other is related to "writing/reading material".

Can you name these two words which also sound similar?

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Before Mount Everest was discovered, what was the highest mountain in the world?