Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

Which alphabet letter is a question?

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?

Which Burger Is Different in below image?

What runs around the whole yard without moving?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Here is a Swiss Cross. You have to make two straight cuts in the figure so that it is divided into four congruent pieces. Also, you should be able to join these pieces into a square then. Can you accept this challenge?

A woman who works in a sweet shop has a measurement of 32-26-36, is 5"4" tall, and wears size "6" shoes. What do you think she weighs?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?