Which of the following pairs of sets are equal ? Justify your answer.
$\mathrm{X} ,$ the set of letters in $“\mathrm{ALLOY}"$ and $\mathrm{B} ,$ the set of letters in $“\mathrm{LOYAL}”.$
$A = \{ x:x \ne x\} $ represents
How many elements has $P(A),$ if $A=\varnothing ?$
Write the following intervals in set-builder form :
$\left( { - 3,0} \right)$