Question

Let,

$A=\{x:x\text{is an even number},x>0\}$

$B=\{x:x\text{is a positive prime number}\}$

$C=\{x:x\text{is a positive perfect square number}\}$

$D=\{x:x\text{is an odd number},x>0\}$

Find which one of the sets are disjoint.

• A. $A,B$
• B. $B,C$
• C. $C,D$
• D. $D,B$

Answer 1

Answer: (B)

$B,C$

Now, according to the problem,

$A=\{2,4,6,8,......\}$, $B=\{2,3,5,7,11,....\}$, $C=\{1,4,9,16,.....\}$, $D=\{1,3,5,7,......\}$.

It is clear that $A\cap B\ne \varphi$, $B\cap C=\varphi$, $C\cap B\ne \varphi$, $D\cap B\ne \varphi ,A\cap D=\varphi$.

So $B,C$ and $A,D$ are the disjoint sets.