Which of the following are examples of the null set?
F = {x : x ϵ Q, 1 < x < 2}.
Here, x ∈ Q
i.e. x is a rational number
We know that,
If a and b are two rational numbers, then is a rational number between a and b such that
So, the rational number 1 and 2 is
∴ the set is not empty
∴ It is not a null set.