What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

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

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Cristina was born in 1888. She just had her 30th birthday today how did that happen?

There are 2 people near the river and both of them want to get on the other side. The boat can only take one of them. But they got across.
How?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

This is a simple one. You just have to count the number of Fs in the given sentence.

Finished Files are the result of years of scientific study combined with the experience of years.

How many did you count?

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?

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