Why do people go to bed?

I start and end with 500 and carry a 5 in my heart. But I require the first letter and the first number to be complete. I am the name of a King.

Who am I ?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

Which is Odd One Out and why?

4377

3954

9862

8454

9831

People are waiting in line to board a 100-seat aeroplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise, they will choose an open seat at random to sit in. The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?

John and his team plan to rob a safe. They got just one chance to break the code else the local police will be informed. Below are clues:
A) Exactly one number is perfectly placed: 9 8 1
B) Everything is incorrect: 9 2 4
C) Two numbers are part of the code of the safe but are wrongly placed: 0 9 3
D) One number is part of the code of the safe but is wrongly placed: 1 4 7
E) One number is part of the code of the safe but is wrongly placed: 7 8 3

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

Can you make four (4) nines (9) equal 100?

Why 1729 is a magic number? Answer Logically.

A boy was at a carnival and went to a booth where a man said to the boy, "If I write your exact weight on this piece of paper then you have to give me $50, but if I cannot, I will pay you $50." The boy looked around and saw no scale so he agrees, thinking no matter what the carny writes he'll just say he weighs more or less. In the end the boy ended up paying the man $50. How did the man win the bet?