SETS (EX 1.4 TO 1.6)

Let A and B be any two sets. The union of A and B is the set

• contains the elements of A only

• contains the elements of B only

• contains the elements of A and B both

• none of these

If A = {2, 4, 6, 8} and B = {6,8,10,12}, then  $A\cup B$   is

• {2, 4, 6, 8}

• {6, 8, 10, 12}

• {6, 8}

• {2, 4, 6, 8, 10, 12}

Consider
A = {1, 2, 3, 4},
B = {3, 4, 5, 6},
C = {5, 6, 7, 8}. The set $A\cup B\cup C$   is

• {1, 2, 3, 4, 5, 6}

• {3, 4, 5, 6, 7, 8}

• {1, 2, 7, 8}

• {1, 2, 3, 4, 5, 6, 7, 8}

 

Let A = {2, 4, 6, 8} and B = {6, 8, 10, 12}. Then, $A\cap B$ 
is

• {2, 4}

• {6, 8}

• {10, 12}

• {2, 4, 6, 8, 10, 12}

 

Two sets are said to be …X…, if  $A\cap B=$  Y.
Here, X and Y refer to

• disjoint, A

• disjoint, B

• disjoint,  $\phi$  

• same,  $\phi$  

Which of the following pairs of sets are disjoint?
I. {1, 2, 3, 4} and {x : x is a natural number and $4\le x\le6$ }
II. {a, e , i, o, u} and {c , d , e , f }
III. {x : x is an even integer} and {x : x is an odd integer}

• I and II

• III

• II

• II and III

Which of the following represent A - B?

• $\left\{x\ :\ x\ \in A\ and\ x\in B\right\}$

• $\left\{x\ :\ x\ \in A\ and\ x\notin B\right\}$

• $\left\{x\ :\ x\ \notin A\ and\ x\in B\right\}$

• $\left\{x\ :\ x\ \in A\ or\ x\in B\right\}$

In a class of 60 students, 25 students play cricket and 20 students play tennis, and 10 students play both the games. Then, the number of students who play neither is

• 0

• 25

• 35

• 45

In a class of 35 students, 24 like to play cricket and

16 like to play football. Also, each student likes to

play atleast one of the two games. The number of

students who like to play both cricket and football, is

• 27

• 43

• 5

• 75

In a city, 20% of the population travels by car, 50% travels by bus and 10% travels by both car and bus. Then, person travelling by car or bus, is

• 80%

• 40%

• 60%

• 70%