How do you go from 98 to 720 using just one letter?

Known by all without exception, Forever here, for your protection, Sometimes strong, sometimes weak, Right after the night I come - hot and chic. And while millions of miles away, I always get to you, I find my way. No life around could do without me, Can you guess what I might be?

What does this rebus photo means?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

I travel all around the world but always stay in the corner. What am I?

In four steps you need to move the word 'cold' From 'warm' by replacing one alphabet at a time such that every word formed at each step is acceptable in English Dictionary.

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

At a party, there are five people and a whole round cake lying at the centre of the table. Only four people will make a cut and take their piece and the last one will get the remaining piece on the table. How can they make sure that everyone gets a 1/5th of the piece?