Answer all question and i want to say for .

These are my guesses:

Who pays taxes?
All of the above.

What are the three main types of taxes?
Income, sales, and property

What is Social Security?
A private insurance system just for the elderly

The purpose of taxes is to
All of the above.

The first one, i believe, would be correct. all the others have one thing in common, and that's that they have repeating numbers. in the second one, x and y have repeating 6's and 3's, and in the third, x and y have repeating 6's as well. in the last one, there are repeating 3's. the first one has no repeating numbers.

The mode of the numbers is 29.