Statement $p:$ "An equilateral triangle is equiangular" then negation of statement $p$ is

Let $p$ be the statement "$x$ is an irrational number", $q$ be the statement " $y$ is a transcendental number" and $r$ be the statement "$x$ is an irrational number iff $y$ is a transcendental number".

Statement-$1:r$ is equivalent to either $q$ or $p$.

Statement-$2:r$ is equivalent to $~\left(p\iff ~q\right)$.

Statement $1: ~(p\leftrightarrow ~q)$ is equivalent to $p\leftrightarrow q$.

Statement $2: ~(p\leftrightarrow ~q)$ is a tautology.

Consider the following statements:

$P$: Suman is brilliant

$Q$: Suman is rich

$R$: Suman is honest.

The negation of the statement "Suman is brilliant and dishonest iff Suman is rich" can be expressed as

The negation of the statement

"If I become a teacher, then I will open a school", is;