You need to remove four matchsticks from the picture below and still need to maintain the following as in the original image.
1. 1st row contains 12 matchsticks
2. 2nd row contains 12 matchsticks
3. 1st column contains 12 matchsticks
4. 2nd column contains 12 matchsticks
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?
In 2007, a puzzle was released and $2 million prizes were offered for the first complete solution. The competition ended at noon on 31 December 2010, with no solution being found. Wiki