Keyboard words are not in alphabetical order, Why?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?

What is black when you buy it, red when you use it, and gray when you throw it away?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

A man escapes from jail using help from his girlfriend. The investigators suspect four girls of being the man's girlfriend.

Out of those four girls, one is his girlfriend who is lying. Two of the girls are completely innocent and are speaking the truth. One of the girls is the man's sister who is helping the girlfriend lie. Following are the statements from all four of them:

Ariana: "Myrna is his girlfriend."
Jane: "Angelina is lying."
Angelina: "Ariana is lying."
Myrna: "Jane is not his sister."

Can you find out who is the man's sister among them?

Which English verb becomes past tense just by rearranging the letters?

Why is it very easy to weigh a fish?

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?