What goes up but never comes down?

No matter how little or how much you use me, you change me every month. What am I?

Find the 8 in the below-given Image.

Accidentally, two trains are running in the opposite direction and enter a tunnel that is 200 miles long. A supersonic bird that has fled the lab and taken shelter in the tunnel starts flying from one train towards the other at a speed of 1000 mph. As soon as it reaches the second train, he starts flying back to avoid collision and meets the first train again at the other end. The bird keeps flying to and fro till the trains collide with each other.

What is the total distance that the supersonic bird has traveled till the trains collided?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

What does does this rebus picture means ?

There are two insects on a tile. Insect X is sitting on one side of the tile (point A) and Insect Y is sitting opposite on the other side of the tile (point B). Now both of them decide to change their position and thus X starts crawling to point B and Y starts crawling to point A. When they meet and pass each other in between, X takes 20 seconds to reach B and Y takes just 5 seconds to reach A.

Can you calculate the total time each of the insects took to change their positions?

What can you see in the middle of March and April that you can never see in any other month?

It is always ahead of me yet I can never see it. What is it?

What is the below Rebus indicate?