Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

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?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

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

Women do it once a year after they turn 19 but men get to do it only once in a lifetime. What is it?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

What has many teeth, but cannot bite?

What does a man do only once in his lifetime, but women do once a year after they are 29?

What is the end of everything?

10+10 and 11+11 can give you the same answer.

Explain how?