What is common among 11, 69, and 88?

A boy purchased a book from a bookkeeper and gave him $100.
The cost of the book is $50 but the bookkeeper has no change, so he gets the change from the next shop and returns the boy his $50.

After some time the next shopkeeper came with the $100 note and told the bookkeeper that the note was a fraud, so he took the money back.

How much loss did the bookkeeper face?

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

The doctor prescribed you to take one pill from the bottle every half an hour. The bottle is now left with only three pills.

How long do you think you have before you run out of pills?

How can you make number one disappear by adding something to it?

A guard is positioned at the one side of the bridge saying ‘A’. His task is to shoot all those who try to leave from ‘A’ to the other side and say ‘B’. He also need to welcome the person who comes from another side ‘B’ to his side ‘A’. The guard comes out of his post every 1 hour and looks down the bridge for any people trying to leave. You are at side ‘A’ and wish to go to another side ‘B’. you also know that it would take 1:45 hr to cross the bridge. How will you cross the bridge?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

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

"That Restaurant always remains crowded. This is the reason why nobody goes there".

Can you find a flaw in this statement?

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