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

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Why is 6 afraid of 7?

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

I have cities, but no houses. I have mountains, but no trees. I have water, but no fish. What am I?

What has a bottom at the top?

In a town, there are over 100 flats.
Flat-1 is named first flat.
Flat-2 is named second flat.
Flat-3 is named third flat.

A visitors 'Victor' decides to walk through all the flats, he finds all the flats except flat-62.
Victor later founds that the local of the town have given it another name.

What is the name of the Flat?

John’s parents have three sons: Snap, Crackle, and what’s the name of the third son?

What do you think with the below Picture ?

Which English verb becomes past tense just by rearranging the letters?