Scroll:set and function >> Choose the correct answer >> mcq (4266)


Written Instructions:

For each Multiple Choice Question (MCQ), four options are given. One of them is the correct answer. Make your choice (1,2,3 or 4). Write your answers in the brackets provided..

For each Short Answer Question(SAQ) and Long Answer Question(LAQ), write your answers in the blanks provided.

Leave your answers in the simplest form or correct to two decimal places.



 

1)  

 If {(x,3)}, (8,y)} represent an identity function,

then (x,y) is _______

(A)  (3,8)    (B) (8,3)    (C)  (3,3)  (D) (8,8)







(                    )




2)  

 For any three sets A,B and C, B\(A∪C) is ______

(A)  (A\B) ∩ (A\C)        (B) (B∖A) ∩ (B∖C)

(C)  (B\A) ∩ (A\C)        (C) (A\B) ∩ (B\C)







(                    )




3)  

 Let A = {1,3,4,7,11}, B = {-1,1,2,5,7,9} and ƒ: A"B be given by ƒ = {(1,-1),(3,2),(4,1),(7,5),(11,9)}. Then ƒis ________








(                    )




4)  

 For any three sets A,B and C, A∪(B∩C) is ______  

(A) (A∪B)∪(B∩C)   (B) (A∩B)∪(A∩C) 

(C) A∪(BC)       (D) (A∪B)∩(B∪C)







(                    )




5)  

 If A = {6,7,8}, B = {2,3,4,5,6}

and ƒ:A"B is defined by ƒ(x) = x- 2, then the range of ƒ is ___






(                    )




6)  

 If n[p(A)] = 32, then n(A) is _____

(A) 2  (B)  4  (C) 6  (D) 3







(                    )




7)  

 If n(A) = 40, n(B) = 50 and n(A∪B) = 30, then n(A∩B) is equal to _______





 

 


(                    )




8)  

If A = {p,q,r,s}, B = {r,s,t,u} then A\B is ______

(A) {p,q}  (B)  {t,u}   (C)  {r,s}   (D) {p,q,r,s}








(                    )




9)  

 If ƒ: A" B is a bijective function and if n(A) = 15,

then n(B) is equal to ____






(                    )




10)  

 Which one of the following is not true

(A) A∖B = A∩B‘          (B) A\B = A∩B

(C) A\B = (A∪B)∩B‘    (D) = A\B = (A∪B)\B





 



(                    )




 

1)  

 If {(x,3)}, (8,y)} represent an identity function,

then (x,y) is _______

(A)  (3,8)    (B) (8,3)    (C)  (3,3)  (D) (8,8)





Answer: 2



SOLUTION 1 :

  If {(x,3)}, (8,y)} represent an identity function the x = 3, y = 8

(x,y) = (3,8)

Ans (A) ⇒(3,8)



2)  

 For any three sets A,B and C, B\(A∪C) is ______

(A)  (A\B) ∩ (A\C)        (B) (B∖A) ∩ (B∖C)

(C)  (B\A) ∩ (A\C)        (C) (A\B) ∩ (B\C)





Answer: 3



SOLUTION 1 :

 B∖(A∪C) = (B∖A) ∩ (B∖C)

Ans (B)    ⇒  (B∖A) ∩ (B∖C)



3)  

 Let A = {1,3,4,7,11}, B = {-1,1,2,5,7,9} and ƒ: A"B be given by ƒ = {(1,-1),(3,2),(4,1),(7,5),(11,9)}. Then ƒis ________





Answer: 2




SOLUTION 1 :

 Each element in A is associated to a unique element in B.

     ƒ is one-one function.

Ans (A) one-one



4)  

 For any three sets A,B and C, A∪(B∩C) is ______  

(A) (A∪B)∪(B∩C)   (B) (A∩B)∪(A∩C) 

(C) A∪(BC)       (D) (A∪B)∩(B∪C)





Answer: 3



SOLUTION 1 :

 Intersection distribution over union

A∪(B∩C) = (A∩B)∪(A∩C) 

Ans (B) (A∩B)∪(A∩C) 



5)  

 If A = {6,7,8}, B = {2,3,4,5,6}

and ƒ:A"B is defined by ƒ(x) = x- 2, then the range of ƒ is ___





Answer: 2



SOLUTION 1 :

 ƒ(x) = x - 2

ƒ (6) = 6 - 2 = 4

ƒ (7) = 7 - 2 = 5

ƒ (8) = 8 - 2 = 6

Range of ƒ = {4,5,6}

Ans (D) {4,5,6}.



6)  

 If n[p(A)] = 32, then n(A) is _____

(A) 2  (B)  4  (C) 6  (D) 3





Answer: 2



SOLUTION 1 :

n[p(A)] = 32

2n(A) = 32

2n(A) = 25

n(A) = 5

Ans(A)5



7)  

 If n(A) = 40, n(B) = 50 and n(A∪B) = 30, then n(A∩B) is equal to _______





Answer: 3

 

 


SOLUTION 1 :

n(A∪B) = n(A) + n(B) - n(A∩B)

   30 = 40 + 50 - n(A∩B)

n(A∩B) = 90 - 30

n(A∩B) = 60

Ans (B) ⇒ 60



8)  

If A = {p,q,r,s}, B = {r,s,t,u} then A\B is ______

(A) {p,q}  (B)  {t,u}   (C)  {r,s}   (D) {p,q,r,s}





Answer: 3




SOLUTION 1 :

 A|B = {p,q,r,s} {r,s,t,u}

       = {p,q}



9)  

 If ƒ: A" B is a bijective function and if n(A) = 15,

then n(B) is equal to ____





Answer: 4


SOLUTION 1 :

ƒ: A" B is bijective ⇒ ƒ is one-one and onto.

ƒ(A) = n(B) ⇒ n(B) = 15

Ans 15 



10)  

 Which one of the following is not true

(A) A∖B = A∩B‘          (B) A\B = A∩B

(C) A\B = (A∪B)∩B‘    (D) = A\B = (A∪B)\B





Answer: 2

 



SOLUTION 1 :

 A∖B ≠ A∩B

Ans (B) ⇒  AB = A∩B