Can you replace the question mark with the correct number?

1 dollar = 100 cent
= 10 cent x 10 cent
= 1/10 dollar x 1/10 dollar
= 1/100 dollar
= 1 cent

=> 1 dollar = 1 cent

solve this tricky problem?

If you go to the movies and you're paying, is it cheaper to take one friend to the movies twice, or two friends to the movies at the same time?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

How can a man go eight days without sleep?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

When we see 2 but call 10?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?