well as far as the first one goes I know that the set of integers Z is a subset of Q and that Z is countable. now I make B as the set of all non-integral rational numbers.
if B is countable, then Q is countable because a union of two countable sets is countable.
that's my approach, but...
I need help with this math problem:
Show that the set of rational numbers, Q, is countable.
and
Show that the set of irrational numbers is uncountable.