Question

Which of the sets are equal sets? State the reason.
$\varphi ,\left\{0\right\},\left\{\varphi \right\}$

Answer 1

Each one is different from others.
$\varphi$ contains no element
$\left\{0\right\}$ contains one element i.e., 0.
$\left\{\varphi \right\}$ contains one element, i.e., the null set