What seven-letter word has hundreds of letters in it?

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

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

Can you move 2 matchsticks to form four equal sized squares.

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

what does the below rebus means?

Can you count the number of triangles in the picture below?

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?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

It is a six-letter word.
The first four letters are me.
The second and last letters are the same.
The fourth second and last letter is payment.

Who is it?