Question
For any set A, (A')' is equal to:
- A'
- A
- $\phi$
- None of these.
Solution:
The complement of the complement of a set is the set itself.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
If $|\text{x}+2|\leq9,$ then:
$\text{x}\in(-7,11)$
$\text{x}\in[-11, 7]$
$\text{x}\in[-\infty,-7)\cup(11,\infty) $
$\text{x}\in(-\infty,-7)\cup[11,\infty) $
If A and B are coefficient of xn in the expansions of (1 + x)2n and (1 + x)2n – 1 respectively, then $\frac{\text{A}}{\text{B}}$ equals:
$1.$
$2.$
$\frac{1}{2}.$
$\frac{1}{\text{n}}.$
Hint:
$\frac{\text{A}}{\text{B}}=\frac{^{2\text{n}}\text{C}_\text{n}}{^{2\text{n}-1}\text{C}_\text{n}}=2$In a non-leap year, the probability of having 53 tuesdays or 53 wednesdays is:
$\frac{1}{7}$
$\frac{2}{7}$
$\frac{3}{7}$
none os these.