Use elements in the order given to determine rows and columns of the matrix.

R on {1,2,3,4} where aRb means |a-b| <1.

R on {1,2,3,4,6,12} where aRb means a|b.

2 answers

Adam, Nat, Martin, Tony, or whoever ~ Don't bother changing names. It's obvious you're all the same.

To quote one of our very good math and science tutors: “You will find here at Jiskha that long series of questions, posted with no evidence of effort or thought by the person posting, will not be answered. We will gladly respond to your future questions in which your thoughts are included.”
Adam, Nat, Martin, Tony,

If you have no clue what the questions are asking, it's high time to do some revision before the finals are here.
Show some efforts and say where you need help. Even answers at the end of a book are intended for comparison with your own answers.