Can you replace the question mark with the correct number in the below table sequence?

A mother bought three dress for her triplets daughters(one for each) and put the dresses in the dark. One by one the girls come and pick a dress.
What is the probability that no girl will choose her own dress?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

Seven Robbers robbed a bank and hide the coins in a lonely place.
They decide to divide the money equally the next morning. Two greedy robbers decided to cheat the others and reach the place at night. They equally divided the coins between them, one coin left. So they called another robber and then they decided to divide equally among the three. Sadly again one coin left. The same thing happened to the 4th 5th and the 6th robber.
However, when the 7th robber reached in the morning, they can divide the coins equally.

How many coins were there in total?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

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?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

On a beautiful Sunday morning, You ordered a hot tea to your hotel room and suddenly you remember an important thing that needed to be done right now will take around 3 minutes to complete.
Like most people you like your tea to be hot while drinking so, when should you pour cream in the tea?
1. straight away
2. Just people, you drink the team
3. Its does not matter

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?