Answer:
a) False
b) False
Explanation:
We are given the following information:
Z is a set of all integers,
is a set of all positive integers and
is a set of all negative integers.
Q is a set of all rational numbers,
is a set of all positive rational numbers and
is a set of all negative rational numbers.
N is a set of all natural numbers.
a) False
We will show this with the help of a counter example.

which is a rational number and not an integer.
b) False
We will show this with the help of a counter example.

which is a rational number and not a natural number.