In an examination,$40 \%$ students failed in Hindi,$50 \%$ students failed in English. If $21 \%$ students failed in both the subjects,find the percentage of those who passed in Hindi.

Given the sets $A = \{1, 2, 3\}$,$B = \{3, 4\}$,and $C = \{4, 5, 6\}$,then $A \cup (B \cap C)$ is:

Let $f:R \to R$ be defined by $f(x) = 2x + |x|$,then $f(2x) + f(-x) - f(x) = $

Find the power set of $A = \{\{a, b\}, c\}$.

In a class of $100$ students, the number of students who passed in English only is $46$, in Maths only is $46$, and in Commerce only is $58$. The number of students who passed in English and Maths is $16$, in Maths and Commerce is $24$, and in English and Commerce is $26$. The number of students who passed in all three subjects is $7$. Find the number of students who failed in all the subjects.

If $U = \{2, 3, 4, 5, 6, 7, 8, 9, 10, 11\}$,$A = \{3, 5, 7, 11\}$ and $B = \{7, 8, 9, 10, 11\}$,compute $(A - B)'$.