What do you answer even though it never asks you questions?

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

There are 100 bulbs in a room. 100 strangers have been accumulated in the adjacent room. The first one goes and lights up every bulb. The second one goes and switches off all the even-numbered bulbs - second, fourth, sixth... and so on. The third one goes and reverses the current position of every third bulb (third, sixth, ninth? and so on.) i.e. if the bulb is lit, he switches it off and if the bulb is off, he switches it on. All the 100 strangers progress similarly.

After the last person has done what he wanted, which bulbs will be lit and which ones will be switched off?

What can run but never walks, has a mouth but never talks, has a head but never weeps, has a bed but never sleeps?

John asked Jack, "The time right now is 7 pm. Can you tell me what will be the time 23, 999, 995 hours later ?"

While Bella does not know the answer, do you ?

What's the best place to go shopping in the ocean?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

By moving exactly three matchsticks can you make the below equation true.It can be solved by 3 ways.

How can you spell "White of an egg" in one word?
Hint: I know you can spell coke, poke, and joke.

What does this Rebus Picture means ?