You can see it everyday, But cannot touch it at will. What is it?

How many words can a pen with half refill write?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

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

One day, I thought of ways that can be used for creating a palindrome. So I decided that I will turn into a larger number by adding the reversed digits to the original number and keep doing it till I finally obtained a palindrome.

I am not sure if this process will always result in a palindrome eventually but I was able to produce a four-digit palindrome. Can you guess my starting number?

If a wheel has 54 spokes, how many spaces are there between the spokes?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

A few friends are enjoying their sea voyage in a boat full of apples. On the way, they felt hungry and thus decided to eat the apples. Together, they ate two dozen of apples. When they have eaten the apples, will there be any change in the water level?

How many triangles are there on the puzzle below?

There was a strange boy who was born before his father. How can this be possible?