Can you solve this picture maths equation?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

Which of the following words don't belong in the group and why?
CORSET, COSTER, SECTOR, ESCORT, COURTS

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?

I have an eye but still cannot see.

Who am I?

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

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

In a Society, there are over 100 flats.

Flat 1 is named the first flat.
Flat 2 is named the second flat.
Flat 3 is named the third flat. And So On.....

A visitor decides to walk through all the flats, and he finds all the flats except flat 62.
Anmol later founds that the locals of the town have given it another name.

What is the name of the Flat?