class 9 set Hint

CW 4:09 AM

Saturday, June 13, 2020

BOOK PAGE 17
EX=2

1) Bystuding the given Venn diagram, fid the cardinal numbers of th following sets

U

a) n(A)=4 A .f B
b) n(B)= 2
c) n( c .g
.d
n( .h .i
d) n(U)= 7 e

e)

f) n

g)
h)
i)
j)

2A) if n(A)=200 , n(B)=300 & A
I) Findthe value of
II) Draw the venn diagram of the above information 300 100 400-100

Solution -100 =300
We have, =200

set 2 Page 1

2B) A& B two subsets of a universal set U in which n(U)= A 60-20=40 B
160 ,(A)= 100 n(B)=60 and
100-20=80 20
I) Show it in a venn diagram
II) Find the value of

SOLUTION

From the venn diagram

3 a) A and B are teo subsets ofa universal set U in which n(U)=129., A B
n(A)=75,n(B)=54 and
I) Draw venn diagram o f above information 75-21=54 21 54-21=33

II) Find the value of

4a) A and B are two subsets ofa universal set U in which n(U)=210., A B
n(A)=120,n(B)=60 and
I) Draw venn diagram o f above information 60
II) Find the value of
45
Now filling in Venn diagram
from Venn diagram

x=15

6a) In a survey of 120 students 60 drink milk , 50 M C
drink curd and 20 students drink milk as well curd 20
then 984619846
60-20=40
i) Draw venn diagram 50-20=30
ii) Find the number of students who neither drink of them

solution
let M &C denote students DRINK milkand curd rrespectively

set 2 Page 2

let M &C denote students DRINK milkand curd rrespectively
So,
n(U)=120
n(M)=60
n( C)= 50

Now, from the venn diagram

30 students likes non of these

7a in a survey of community , 55% of the people like to listen the radio, 65% like to watch

the television and 35% like to listen radio as well as to watch the television

I) Draw venn diagram

II) Find the number of people who donot like to listen neither of them R T
65-35=30
Solution

Let R and T denote the people who like to listen radio and tV ..

n (U) = 100 % n( R) = 55% n(T) = 65% 35

from venn diagram 55-35=20

15% people who donot like to listen neither of them

8b) out of 200 students in an examination of IX , 140 passed in math , 120 passed in science
and 40 failed in both subjects. Find the number of students who passed in both by using
Venn diagram
Solution
let M and S denotes the sets of students who passed in math and science respectively
n(U)=
n(M)=
n(s)=

from Venn diagram

9b) A group of 140 people , 74 likes tea ,104 like milk and each person likes at least one of
the two drinks
i) How many people like both tea and milk ?
ii) how many people like tea only
iii) How many people like milk only?

set 2 Page 3

iii) How many people like milk only?
Solution
let ….
n(U)= 140
n(T)=
n(M)=

we have

10 b) In a survey of 90 people it was found that 51 liked to eat orange and 59 liked to eat
apple .If there were 3 people who did not like to eat both fruits
i) How many people liked to eat only orange?
ii) How many people liked to eat only apple?
iii) show above information in the Venn diagram
Solution
Let O and A denotes the …
n(U)=
n(O)=
n(A)=

we have ,
n(U) =

using in Venn diagram
11b) In a examination , 80 students secured first class marks in English or Math .
Out of these 50 students obtained first class marks in Math and 10 student in
English and Math both . How many students get first class marks in English only?
solution
Let …

n(M)=

we have ,

12b)
n(U) = 300
n(M)=240
n( E ) =

from Venn diagram

set 2 Page 4

from Venn diagram

13 b)
Solution
Let …
n(U)= 100
n(O) = 80
n( M) = 85

let

from Venn diagram

so, 10% of total =333

total = 3330
14 b) Let
n(U) =100
Ratio of youth who like anroid and Ipad = 3:5
n(A) =3x
n(I)=5x
from Venn diagram
n(U) =
100 =

set 2 Page 5