Can you solve the maths in the below-given picture equation?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Name a key which is hardest to turn.

What is the next number?

77, 49, 36, 18 ?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Can you solve below mathematical equation?

2^1234 - 2^1233

Find the value of "?" in the ball picture Riddle below:

John, a 5-year-old boy, was really fond of the chocolates. He asked his Mother to give him some money to buy his favourite chocolates. His Mother gave him $45. He went to the shopkeeper and asked, "How much is one chocolate for?". The shopkeeper said $3 for one chocolate. Also, if you give me the wrappers of three chocolates, I will give you one for the exchange.
In total, how much chocolate could John eat?

Look at me. I can bring a smile to your face, A tear to your eye, Or even a thought to your mind. But, I can't be seen. What am I?