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 ƒ(x) = x2 + 3, then ƒ(-6) = ____





 


(                    )




2)  

 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





 



(                    )




3)  

 If {(6,14), (2,z)} represent a constant function,

then the value of 'z' is _______

(A) 6    (B) 14     (C) 2    (D) 8








(                    )




4)  

 For any two sets A and B, {(A\B)∪(B\A)} ∩ (A∩B) is _____

(A) ∅   (B) (A∪B)   (C) (A∩B)    (D) A‘∩B‘






{(A\B)∪(B\A)} ∩ (A∩B) = {(A∪B)∖(A∩B)}∩(A∩B)

                                  = ∅

Ans (A) = ∅


(                    )




5)  

 If n(A) = 20, n(B) = 50 and n(A∪B) = 30, then n(A∩B) is equal to _______





 

 


(                    )




6)  

 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)







(                    )




7)  

 If {(x,3)}, (9,y)} represent an identity function,

then (x,y) is _______

(A)  (3,9)    (B) (9,3)    (C)  (3,3)  (D) (9,9)







(                    )




8)  

 If ƒ: A" B is a bijective function and if n(A) = 18,

then n(B) is equal to ____






(                    )




9)  

 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 ________








(                    )




10)  

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}








(                    )




 

1)  

If ƒ(x) = x2 + 3, then ƒ(-6) = ____





Answer: 4

 


SOLUTION 1 :

 ƒ (x) = x2 + 3

ƒ (-6) = (-6)2 + 3

                 = 36 + 3 = 39

Ans   ⇒  39



2)  

 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



3)  

 If {(6,14), (2,v)} represent a constant function,

then the value of 'v' is _______

(A) 6    (B) 14     (C) 2    (D) 8





Answer: 3




SOLUTION 1 :

  If {(6,14), (2,v)} represent a constant function,

then the value of  v = 14

Ans   (B) ⇒ 14



4)  

 For any two sets A and B, {(A\B)∪(B\A)} ∩ (A∩B) is _____

(A) ∅   (B) (A∪B)   (C) (A∩B)    (D) A‘∩B‘






Answer: 2

{(A\B)∪(B\A)} ∩ (A∩B) = {(A∪B)∖(A∩B)}∩(A∩B)

                                  = ∅

Ans (A) = ∅


SOLUTION 1 :

{(A∖B)∪(B∖A)} ∩ (A∩B) = {(A∪B)∖(A∩B)}∩(A∩B)

                                  = ∅

Ans (A) = ∅



5)  

 If n(A) = 20, 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 = 20 + 50 - n(A∩B)

n(A∩B) = 70 - 30

n(A∩B) = 40

Ans (B) ⇒ 40



6)  

 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) 



7)  

 If {(x,3)}, (9,y)} represent an identity function,

then (x,y) is _______

(A)  (3,9)    (B) (9,3)    (C)  (3,3)  (D) (9,9)





Answer: 4



SOLUTION 1 :

  If {(x,3)}, (9,y)} represent an identity function the x = 3, y = 9

(x,y) = (3,9)

Ans (A) ⇒(3,9)



8)  

 If ƒ: A" B is a bijective function and if n(A) = 18,

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) = 18

Ans 18 



9)  

 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: 1




SOLUTION 1 :

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

     ƒ is one-one function.

Ans (A) one-one



10)  

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: 4




SOLUTION 1 :

 A|B = {p,q,r,s} {r,s,t,u}

       = {p,q}