what does the below math rebus puzzle mean?

Can you find the missing letter in the sequence?
S - T - I - L - ? - T - F - Y - C

Can it be possible to build a house that has all its four walls facing towards the South?

Can you find the company name in the pictogram below?

What is the coolest letter in the alphabet?

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

How can you throw a ball as hard as you can and have it come back to you even if it doesn't hit anything there is nothing attached to it and no one else catches or throws it.

If Japan and Panama decided to merge into a single country, probably people will name it Japanama.

Can you think of two more such country's unions that could produce similar names like Japanama by overlapping their three letters?

It's a protector.
It sits on a bridge.
One individual can see directly through it, while others wonder what it hides.

What is it?

A sea diver is a real show-off. He showed everyone that he can hold his breath underwater for 15 minutes.

I went to the diver and told him that I can be underwater for double the time i.e 30 minutes.
He responded that he will give me 100$ if I would be able to do it. I won 100$.

What did I do?