Assume that $P(A)=P(B) .$ Show that $A=B$.
Examine whether the following statements are true or false :
$\{a\} \subset\{a, b, c\}$
Write the following sets in the set-builder form :
$\{ 3,6,9,12\}$
Write the solution set of the equation ${x^2} + x - 2 = 0$ in roster form.
Let $A=\{1,2,\{3,4\}, 5\} .$ Which of the following statements are incorrect and why ?
$\{1,2,5\}\in A$