The numbers of proper subset of the set $(3, 4, 5, 6, 7)$ is

If $A = (1, 2, 3, 4, 5, 6, 7)$ and $B = (2, 4, 6, 8)$. Cardinal number of $A - B$ is:

$ (A^c)^c = ?$ Note: This que is from matrix (deleted topic).

Two finite sets respectively have $x$ and $y$ number of elements. The total number of subsets of the first is $56$ more than the total number of subsets of the second. The value of $x$ and $y$ respectively.

The set of cubes of the natural number is:

The number of integers from $1$ to $100$ which are neither divisible by $3$ nor by $5$ nor by $7$ is

In a town of $20,000$ families it was found that $40\%$ families buy newspaper $A$, $20\%$ families buy newspaper $B$ and $10\%$ families buy newspaper $C$, $5\%$ families buy $A$ and $B$, $3\%$ buy $B$ and $C$ and $4\%$ buy $A$ and $C$, if $2\%$ families buy all the three newspaper, then the number of families which buy only $A$ is: