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

Complete the table series riddle by finding the number that can replace "??".

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Can you name three consecutive days without using the words Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, or Sunday?

Which is the smallest number that you can write using all the vowels exactly once?

In a classic wine shop, the list of three most popular wines are:
- The cost of 1 French wine bottle: 500$
- The cost of 1 German wine bottle: 100$
- The cost of 20 Dutch wine bottles: 100$

John entered the wine shop and he needs to buy
- All three types of wine bottles.
- Needs to buy Dutch wine bottles in multiples of 20.
- Need to buy 100 wine bottles in total.

John has only 10000$. How many wine bottles of each type, John must buy?

Can you name four days which start with the letter 'T'?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

Use only one mathematical symbol and all numbers (0-9) to get a sum of 99