What you cannot hold but it is yours?

What kind of band never plays music?

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

Count the number of triangles in the picture below:

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

What is black when you buy it, red when you use it, and gray when you throw it away?

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?

I have no life, but I can die. What am I?

Which part of London exists in France as well ?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?