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

If,

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

Then

4 / 5 = ?

What Time Should the last watch show in the below figure?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

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

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211

Christina, Allison and Lena are 3 daughters of John a well-known Mathematician, When I asked John the age of their daughters. He replied "The current age of her daughters is prime. Also, the difference between their ages is also prime."

How old are the daughters?

Baseball bat and ball cost $100. If the bat cost $99 more than the ball, what is the cost of each?