Replace the question mark with the number below given a simple math problem.

How can you make number one disappear by adding something to it?

Why is the Hole below a Lock?

When 99 is considered higher than 100?

Can you solve the photo plexer logic ?

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?

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?

How many triangles can you count in the figure given?

You visit a home for specially-abled children on the occasion of Christmas where you meet with 50 children. You have a box of chocolates containing 50 chocolates exactly.

What if you were asked to one chocolate to each child in a manner that one chocolate still remains in the box? Is it possible?

What is the word or phrase below?
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