What building has the most stories?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

If,

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

Then

4 / 5 = ?

Given below is simple addition with a defined pattern pattern:
7 + 7 = 2
8 + 8 = 4
8 + 5 = 1
6 + 9 = 3
10 + 11 = 9

Can you analyze the pattern and find out the answer for:

4 + 9 = ?

In a science lab, a petri dish hosts a healthy colony of yeast for an experiment. Now every minute, all the yeast cells divide into two. At noon, there was just a single cell of yeast and at 1:22, the Petri dish was half full. Can you calculate when the dish will be full of yeast?

Can you identify the Oscar-winning movie from the rebus below?

What do you answer even though it never asks you questions?

As you can see in the picture, you have a hole with dimensions 9 ft x 2 ft Also available is a wooden board with dimensions 6 ft x 3 ft Now you have to cover the hole with this board and you are allowed to cut the board into two pieces. Please see that the hole is completely covered and the boards should not overlap or extend beyond the edge. How will you cut the board?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

Which famous Hollywood movie name is hidden in the below rebus?