Name a key which is hardest to turn.

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?

I am something people love or hate. I change peoples appearances and thoughts. If a person takes care of them self I will go up even higher. To some people I will fool them. To others I am a mystery. Some people might want to try and hide me but I will show. No matter how hard people try I will Never go down. What am I?

The more of this there is, the less you see. What is it?

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

How high do you have to count before you use the letter “a” in the English spelling of the whole number?

What comes
Once in a Year
Twice in a Month
4 times in a Week
6 times in a Day

Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?

What is next number in the pattern below:

131 517 192 123 ?

You knock a Table over in the library, and suddenly 20 eyes are looking at you.