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

Solve The below Equation:

ALFA + BETA + GAMA = DELTA

A man is found hanging dead from the ceiling of a room. The room’s dimensions are 15 x 15 x 15. The man is only 6ft tall and the rope was only 2ft long. There are no windows and only one door to the room. The door is bolted shut from the inside, and a puddle of water is under the man. How did he kill himself?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

Replace the question mark with the correct number below.

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Solve the equation in the image by looking at the pattern closely.