In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

The more of this there is, the less you see. What is it?

Replace the question mark with the correct number in below Picture:

An office is divided into 8 cubicles. How many of the cubicles are painted if only 1/8 of the cubicles are painted?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

Outside a tattoo artist's shop, there was a signboard which read 'I make tattoos on only them who do not tattoo themselves'.

Reading it what do you think, does the tattoo artist tattoo himself?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"