what's the probability of getting a king or a queen from a pack of 52 cards?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

When can we add 2 to 11 and get 1 as the correct answer?

A man had five children. He had $100 with him to give to his children. He decided to start with the youngest child and then give $2 more than each younger child to his next elder child.

For example, if he gives $x to the youngest child, he will give $(x+2) to the next one, $[(x+2) + 2] to the next one and so on.

Can you find out how much did the youngest one receive?

What four weights can be used to balance from 1 to 30 pounds?

There were five men at church, and it started raining while they were outside. The four that ran still got wet, but the one that was still stayed completely dry. Why did he stay dry?

Find the last number in the series below:

voN luJ yaM raM ---

Count the number of triangles in the below picture?

When I go in I might cause pain. I cause you to spit and ask you not to swallow. I can fill your hole. What am I?

Eight of us go fourth, not back, to protect our king from an attack. What are we?