A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

How many times can you subtract the number 5 from 25?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

The answer I give is yes, but what I mean is no. What was the question?

What is the Surname of Barbie Doll?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

I have eight fingers and two thumbs but I do not live. What Am I?

An evil man kidnapped someone and made them take one of two pills. One was harmless, but the other was poisonous. Whichever pill the victim took, the kidnapper took the other one. The victim took their pill with water and died. The kidnapper survived. How did the kidnapper get the harmless pill?