A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

When it is alive we sing, when it is dead we clap our hands. What is it?

Can you replace the question mark with the correct letter?

6 + 6 + 6 = N
7 + 7 + 7 = E
8 + 8 + 8 = R
0 + 0 + 0 = ?

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

How many times in a given day, minutes and hour clock comes in a straight line ?

When it's bad luck to meet a black cat?

By removing one matchstick and adding one matchstick, can you convert the word "ZOO" to an animal name?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C