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

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

10+10 and 11+11 can give you the same answer.

Explain how?

Why is the Hole below a Lock?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Below toothpicks/matchsticks indicate the group of fishes moving from west to east direction. Can you make them move from east to west by just moving three toothpicks/matchsticks?

Spelt forwards I’m what you do every day, spelled backwards I’m something you hate. What am I?

Let's play a word game. Following are some meaningless words that can be completed by adding random letters on either side of the word.

For example, the word "rdo" can be formed into "pardon".

Using the same technique, can you complete the given words?
ecalc
airb
rinci
tibac
uidel
gorit
igna
eyho

Which number should replace the question mark?