Determine whether each binary relation is reflexive, symmetric, antisemmetric and/or transitive. Justify each one.

1. The relation R on the natural numbers where aRb means that a has the same number of digits as b.

2. The relations S on {a,b,c} where

S = { (a,a), (b,b), (c,c), (a,b), (a,c) , (c,b) }

3. The relation T on the integers where aTb means....

| a - b | <= 1.

Any help please? Thank you