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

How can you write nineteen in a manner that if we take out one, it becomes twenty?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

It is an eleven letter word.
The first, second, third and fourth letters form a banquet's name.
The fifth, sixth and seventh letters form a car's name.
The eighth, ninth, tenth and eleventh letters form a mode of transport.

Can you identify what word it is?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?