Can you arrange four 9's and use at most 2 math symbols, to make the total 100?

We are a group of eight brothers. We consider the weak, yet we protect the king in every battle. If we move ahead, we never turn back. Who are we?

A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

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

What does below pictogram mean?

Rectify the following equality 101 - 102 = 1 by moving just one digit.

What number should come in place of the question mark below?

What is harder to catch the faster you run?

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

I know a nine-letter word having only one vowel.
Do you ?