What's the only room from which no one can enter or leave

what does the below rebus mean?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

A doctor and a boy were fishing. The boy was the doctor’s son, but the doctor was not the boy’s father. Who was the doctor?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

What number do you get when you multiply all of the numbers on a telephone's number pad?

In which direction should the missing arrow point?

What is always in front of you but can’t be seen?

Bobby and Wilbur decided to take their respective car out of the garage and race. None of them cheated and they both stood at the start time and decided to cover a distance in full throttle. The first to reach the mark was to be declared the winner.

Upon reaching the finishing mark, they found out that Bobby's car was 1.2 times faster than Wilbur's. Now, Wilbur had reached the mark about 1 minute and 30 seconds later than Bobby. Bobby's car reached the mark of 60 MPH on average.

Can you calculate the distance between the starting mark and the final mark with the help of the given data?