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

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

Replace the question mark with the correct number in the below-given picture?

He loves to dance, twist and prance, he shakes his tail, and as a way he sails, wingless he flies into the sky. What is he?

In the image below, you can see two glasses and two matchsticks.You need to move four matchsticks in such a manner that the crosses come inside the glasses. Note: you cannot move the crossed.

All of you like to eat me. I am a five-lettered word. Remove the first two and I turn into an infamous animal. Remove just the first and I become a heinous crime. Remove the first and the last and you can groove on me.

Can you guess who am I?

How many triangles are there on the puzzle below?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

What does this Rebus Picture means ?