If $n(A) = 4$,$n(B) = 3$,and $n(A \times B \times C) = 24$,then find $n(C)$.

If $A$ and $B$ are two sets,then $A \cup (A \cap B)$ is equal to

Let $a > 0, a \neq 1$. Then,the set $S$ of all positive real numbers $b$ satisfying $(1+a^2)(1+b^2) = 4ab$ is

Which of the following is a set? Justify your answer.
The collection of ten most talented writers of India.

Let $A = \{1, 2, 3, \ldots, 10\}$ and $B = \left\{\frac{m}{n} : m, n \in A, m < n \text{ and } \gcd(m, n) = 1\right\}$. Then $n(B)$ is equal to:

The solution set of the congruence $x \equiv 3 \pmod{7}$ is given by: