Test: Set Theory- 2 - CAT MCQ

The correct answer is D as
 R = ((1, 1), (3, 1), (2, 3), (4, 2))
RoR=R²=((1, 1), (3, 1), (2, 3), (4, 2))((1, 1), (3, 1), (2, 3), (4, 2))
     =((1, 1), (3, 1), (2, 1), (4, 3))
take the first set (1,1) then take the second element of this subset check in the other set R is there any starting with 1 if yes then take its second element and make a subset in R² similarly check for all.
like (4,2) (2,3)=(4,3)in R²

Let X was the people who speaks all three languages.
Total number of people = (Hindi + English + Kannad) - (Hindi and English + Hindi and Kannad + Kannad and English) + X

28 = (15 + 22 + 18) - (9 + 11 + 13) +X

X = 28 - 55 + 33

X = 6.

The correct answer is C as
Let,the number of voters (experts) be denoted as x
A/Q
 X/2+2x/3-10+6=x
7x/6-4=x
7x-24=6x
x=24
 

a) Since x - x = 0, m
=> x - x is divisible by m
(x,x) ∈ R
=> R is reflexive
b) Let (x,y) ∈ R
=> x - y = mq for some q ∈ I
=> y - x = m(-q)
y - x is divisible by m
(y,x) ∈ R
=> R is symmetric.
c) Let (x,y) and (y,z) ∈ R
=> x - y is divisible by m and y - z is divisible by m
=> x - y = mq and y - z = mq' for some q, q' ∈ I
=>(x-y)+(y-z) = m(q+q')
=> x - z = m(q + q'), q + q' ∈ I
(x,z) ∈ R
=> R is transitive.
Hence the relation is equivalence relation.