I noticed one of the words in the oxford dictionary is spelled incorrectly. What about you?

What is the next number in this series?

4,12,84,3612....

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

I never was there, I am always to be.
You have never ever seen me, not ever you will.
Yet I am the confidence of everyone.

Who Am I?

How can you tell a raw egg from a hard-boiled egg?

What number comes next in the series?

5 15 5 18 5 24 14 20 _

What's a single-digit number with no value?

How many times can you subtract the number two from the number fifty?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

Can you place six X (crosses) in below board without making three in a row in any way ?