What's the only room from which no one can enter or leave

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

There are forty elephants and they have forty-fore heads. How can this be possible?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

How many letters are in the alphabet?

You are a cab driver who pools passengers. You pick 3 people from a destination and drop 1 after an hour. 2 people climb aboard at the same time and you drop 3 at the next destination. After some time, you pick 2 passengers only to drop 1 after a short distance where 3 more passengers climb up the cab. You leave the rest of the passengers one by one to their destination and then come back home.

Can you tell the eye color of the cab driver?

Which point will the car reach to go out?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

A woman who works in a sweet shop has a measurement of 32-26-36, is 5"4" tall, and wears size "6" shoes. What do you think she weighs?

What part of Turkey has the most feathers?