Name one eight-letter word with 'kst' in the middle, 'in' the beginning, 'and' at the end.?

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Two men are in a desert. They both have packs on. One of the guys is dead. The guy alive has his pack open, and the guy who is dead has his pack closed. What is in the pack?

Find the 8 in the below-given Image.

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