Complement of a Set

Q. In a town of $10000$ families, it was found that $40\%$ families buy newspaper $A$, $20\%$ buy newspaper $B$ and $10\%$ 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 newspapers, then number of families which buy newspaper $A$ only is

Q.

Let U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

A = {1, 2, 3, 4}

Then, $A^c$ is

1. {1, 2, 3, 4}

2. {5, 6, 7, 8, 9, 10}

3. {2, 3, 4, 5, }

4. None of these

Q. If $U=\{11,12,13,14,15,16\},$ and $A=\{12,14,16\}$, then $A^{\prime }$ is:

1. $\{11,13,15\}$
2. $\{11,15,18\}$
3. $\{11,13,16\}$
4. $\{12,13,15\}$

Q. If a matrix $A$ consists of $n$ number of elements and $m$ is the possible number of order(s) for matrix $A$, where $(n>0),$ then which of the following is always correct

1. $m>2,$ when $n$ is not prime.
2. $m=2,$ when $n$ is prime.
3. $m>2,$ when $n$ is prime.
4. $m=1,$ when $n$ is prime.