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?

Prove that twice of ten is the same as twice of eleven.

What has one eye, but can’t see?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

1. Where does Easter come from before Valentine's Day?

2. Do you know what is in the middle of Valentine's?

3. What did the lady bee say to the man bee on the occasion of Valentine's Day

Can you find out the total number of triangles in the given figure?

How many pluses should we put between the digits of 987654321 to get a total of 99, and where?

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

A person was killed at a house party. When the police arrive, there are six people present in the house who are the friends of the victim. The name of the friends is Rohit, Aman, Nick, Gagan, and Randy.

Near the dead body, they find a few numbers written with blood by the victim on the floor. The numbers are 8, 5, 4, and 11.

The police arrests one of the friends for the murder. Whom did they arrest and why?

why number 8549176320 is one of a kind?