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?

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

What is so fragile that saying its name breaks it?

What has many teeth, but cannot bite?

I am sure no one can have two things for dinner. what are they?

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?

I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Replace the question mark with the correct number below.