You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?

I am written with two letters.
I said with the one.
I usually am seen with the two.

Who am I?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

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?

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

In a school, 280 students studied chemistry, 254 students studied physics and 280 students studied biology.

97 students studied chemistry as well as physics, 138 students studied physics as well as biology and 152 students studied chemistry as well as biology.

73 students studied all the three branches.

Can you find out the total number of students?

In which direction should the missing arrow point?

A bomb exploded in a room full of married couples and no one died. How?

Take away the whole and some still remain. What is it?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=