Replace the question mark with the number below given a simple math problem.

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

What kind of tree can you carry in your hand?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

who is silent in the parliament?

After teaching his class all about Roman numerals (X = 10, IX=9 and so on) the teacher asked his class to draw a single continuous line and turn IX into 6. The teacher's only stipulation was that the pen could not be lifted from the paper until the line was complete.

I never stop running even when I standstill. If I am formed by joining two identical bodies together, can you guess who I am?

Can you count the number of triangles in the given picture?

I look flat, but I am deep. Hidden realms I shelter. Lives I take, but the food I offer. At times I am beautiful. I can be calm, angry, and turbulent. I have no heart but offer pleasure as well as death. No man can own me, yet I encompass what all men must have. What am I?