XI Maths Sets

If

 $A\cap B=B$ , then :

•  $A\subseteq B$  

•  $B\subseteq A$  

•  $A=\phi$  

•  $B=\phi$  

Which of the following is an empty set ?

• $\left\{x:\ 8\le x<9,\ \ x\in N\right\}$

• $\left\{x:\ x<1,\ x>3,\ x\in Z\right\}$

• $\left\{x:\ \ x^2=4,\ \ x\in R\right\}$

• $\left\{x:\ \ \left|x\right|<3,\ \ x\in R\right\}$

If

 $P=\left\{a,\ b,\ c,\ d\right\}$ which of the following is false ? 

•  $\left\{b\right\}\subseteq P$  

•  $\left\{b,c\right\}\in P$  

•  $\phi\subseteq P$  

•  $c,d\in P$  

 $Let\ A=\left\{1,2,\left\{3,4\right\},5\right\}$  which of the following is false?

•  $\left\{3,4\right\}\subseteq A$  

•  $\left\{3,4\right\}\in A$  

•  $\left\{2\right\}\subseteq A$  

•  $\left\{2,5\right\}\subseteq A$  

 $If\ \ A\cap B\ '\ =\phi$  then :

•  $B\subseteq A$  

•  $A=B$  

•  $A\subseteq B$  

• none of these

 $If\ \ n(U)=50,\ n(A)=30,\$   $n\left(A\cap B\right)=12\ \ and\$   $n\left(\left(A\cup B\right)'\right)=15,\$   $then\ n\left(B-A\right)=?$  

• 3

• 4

• 5

• 6

which of the following statement is true?

• $P\left(A\right)-P\left(B\right)=P\left(A-B\right)$

• $P\left(A\right)\cup P\left(B\right)=P\left(A\cup B\right)$

• $P\left(A\right)\cap P\left(B\right)=P\left(A\cap B\right)$

• None of these

If A={1, 2, 3, 6, 11, 18, 21}, B={5, 7, 9} and N is the universal set, then $A'\cup\left(\left(A\cup B\right)\cap B'\right)$ is equal to : 

•  $A$  

•  $B$  

•  $N-A$  

•  $N$  

The group of honest persons is :

• a null set

• a finite set

• an infinite set

• not a set

Let A= {x: x is a digit in the number 3591}, B= {x: x∈N, x<10}. which of the following is not true ?

• $A\cap B=\left\{1,3,5,9\right\}$

• $A-B=\phi$

• $B-A=\left\{2,4,6,7,8\right\}$

• $A\cup B=\left\{1,2,3,5,9\right\}$