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

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

How is a fly different from a mosquito?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

A high school has a strange principal. On the first day, he has his students perform an odd opening day ceremony:

There are one thousand lockers and one thousand students in the school. The principal asks the first student to go to every locker and open it. Then he has the second student go to every second locker and close it. The third goes to every third locker and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth locker, and so on. After the process is completed with the thousandth student, how many lockers are open?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?