What does this mathematical rebus means ?

Replace the question mark in the picture below.

Which statement is true out of the following?
One statement here is false.
Two statements here are false.
Three statements here are false.

Complete the series by replacing "?" with the correct number.

ST ND RD TH '?'

What begins with T, ends with T, and has T in it?

Which point will the car reach to go out?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

What seven-letter word has hundreds of letters in it?

What does below science rebus mean?

Ag Ag Ag
Ag SPOON Ag
Ag Ag Ag