Find the next number in the sequence

5 12 24 36 ?

What is black when you buy it, red when you use it, and gray when you throw it away?

What number divided by 4 is the same as that number minus 4?

A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside.
The man said, "Oh! I am really sorry, I thought this was my room."
He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man.
What made her suspicious of that man? He might have been genuinely mistaken.

What do you answer even though it never asks you questions?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.

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?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

What is 3/7 chicken, 2/3 cat and 2/4 goat?