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?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

O_er_t_o_

Complete the missing letters of the given word.

Can you place three balls such that the equation shown in the picture holds true?

Can you find the missing piece of the Porsche?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

If two's company, and three's a crowd, then whats four and five ?

Which three-digit number, made of consecutive digits, like 567, is 2 less than a cube and 2 more than a square?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?