Replace the question mark with the correct number below.

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Can you name four days which start with the letter 'T'?

Can you find a number that lies one third of the distance between 1/3 and 2/3?

Where do you go to learn how to make ice cream?

Do you know who was buried in John's tomb?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

Two boys were admitted to a school. When the headmaster asks them about their parents, they tell him that they have same parents (father and mother). On further inquiry, it turns out that they both share the same date for their birthday.

"Are you twins," ask the headmaster.
"No," replies the boys.

Is it possible?

What always comes into a house through the keyhole?