Before Mount Everest was discovered, what was the highest mountain in the world?

If eleven plus two equals one, what does nine plus five equal?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

I am a five-letter word and comprises two different vowels and three same consonants. I am so strong that I can spoil your entire work.

Can you find out who am I?

I have a head like a cat and feet like a cat, but I am not a cat. What am I?

I hide my treasure in the ground, my tail is big and fluffy. If you spot me in a tree, please don’t call me scruffy. What am I?

I can sizzle like bacon,
I am made with an egg,
I have plenty of backbone, but lack a good leg,
I peel layers like onions, but still remain whole,
I can be long, like a flagpole, yet fit in a hole.

There are five vowels (a, e, i, o, u) in the English language.
Can you tell us a word that contains all these vowels?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

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