Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

What country can make you shiver?

Before Mount Everest was discovered, what was the highest mountain in the world?

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?

Our product and our sum always give the same answer. Who are we?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?

What is always in front of you but can’t be seen?

What do you answer even though it never asks you questions?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

When we see 2 but call 10?