Name the three-letter word that can complete the below words?

A) L O _ _ _ E
B) E D U _ _ _ E
C) _ _ _ E R
D) _ _ _ T L E

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

O_er_t_o_

Complete the missing letters of the given word.

Replace each alphabet with the number (1-9) to make the below equation correct.

AB * C = DE - F = GH / I

What does below Rebus say?

XLR8

In the image given, you can find several triangles. Can you count them all?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

What does does this rebus picture means ?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?

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?