How many times in a given day, minutes and hour clock comes in a straight line ?

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

How can one talk without saying a single word?

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

On a magical land of Mexico , all the animal in the land are rational.

There are 10 tigers and one goat.
Tiger can eat goat but since it's a magical land , the tiger who eats the goat , turns into goat and then can be eaten by the remaining tiger(s).

If we leave them for some time then how many goat and tiger will be there , when we come back ?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

A girl rode into a tourist spot out of the city on Thursday. She loved the place and decided to stay for a few days. She stayed for four days and then she left for back home on Thursday.

How can this be possible?

An artist while painting a scenic beauty, decides to paint three layers of blue colour on the sky.

Which layer will go on the first?

How many bricks does it take to complete a building that is 15 feet wide, 30 feet deep, and 12 feet tall made of brick?