Using Only Five 5's and any mathematical operator make sum as 37

What is the word or phrase?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

John was piloting a plane behind a car but was never able to overtake it. Why?

It's a 7-letter word.
If we remove 1 letter from it, it remains the same.
If we remove 2 letters from it, it remains the same.
If we remove 3 letters from it, it remains the same.
If we remove all the letters from it, still it remains the same.
What is it?

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

Can you name an animal whose killing cannot be performed without spilling your own blood?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

In the given picture, in how many ways can you read the word "Tiger"?

What has no start, end, or centre?