Why Aeroplane windows are round?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?

John can place six large boxes or nine small boxes into a carton.

Can you find out in how many cartons can he place sixty-six boxes in total?

It has horns but can’t beep. It is like to bleat but It is not a sheep. What is it?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

What is the next number?

77, 49, 36, 18 ?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

Can you identify if it's a murder or a suicide ?

A man was gazing through the window of the 23rd floor of the building. He suddenly opened the window and jumped on the other side of the window. On landing on the floor, there was not a sheer mark of injury on him.

How can that be possible if he did not use any kind of parachute and did not land on a soft surface?