Topic: Chapter 1: Sets, Relations and Functions (Test 3)



Topic: Chapter 1: Sets, Relations and Functions
Q.1
If n(A) = 2 and n(B C) = 3, then n[(A x B) (A xC)] is
A. 23
B. 32
C. 6
D. 5
Answer : Option C
Explaination / Solution:


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Q.2

If two sets A and B have 17 elements in common, then the number of elements common to the set A x B and B x A is

A. 217
B. 172
C. 34
D. insufficient data
Answer : Option B
Explaination / Solution:


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Q.3
For non-empty sets A and B, if A B then (A x B) (B x A) is equal to
A. A ∩ B
B. A x A
C. B x B
D. none of these
Answer : Option B
Explaination / Solution:


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Q.4
The number of relations on a set containing 3 elements is
A. 9
B. 81
C. 512
D. 1024
Answer : Option C
Explaination / Solution:

Let S = {a,b,c}

n(S) = 3 

n(S x S) = 9

Number of relations in n{P(SxS)} = 29  = 512



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Q.5
Let R be the universal relation on a set X with more than one element. Then R is
A. not reflexive
B. not symmetric
C. transitive
D. none of the above
Answer : Option C
Explaination / Solution:

Let X ={a,b,c}

Then R = Universal relation

= {(a,a), (a,b)(a,c)(b,a), (b,b)(b,c)(c,a), (c,b)(c,c)}



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