Monday, May 17, 2021

ML AGGARWAL CLASS 7 Chapter 5 Sets EXERCISE:5.1

 EXERCISE:5.1


Question 1

i) All state of india 

ii) Last three days of a week 

iii) All months of a year having atleast 30 days 

The above three are set because they are well defined 

Remaining all are not sets, they are not well defined 

Question 2

(iii) and (iv) are two 

(i) is false because C is not a vowel

(ii) is false because {a} is a set and not element 

(iii) is false because b is not vowel , so $b \notin A$ of course , $a \in A$

(v) is false , {a,i ,u} is a set and not elements 


Question 3

(i)The set of first six letters of alphabet

ii) {prime numbers less than 20 }

iii) {last three days of a weet }

iv) {months of a year whose name being with a vowel}


Question 4

i) $\{12,14,16,18,20,22 \ldots \ldots, 48\}$ ;$\{x: x=2 n, n \in N$ and $5<n<25$}

ii) { Jan, Mar, may, July, Aug, oct, Dec }

{$x \mid x$ is a month of a year having more than 30 days}

iii) {0,1,4,9},{x $\mid x$ is a perfect square one digit number}

iv) {1,2,3,4,6,9,12,18,36} ;{x $\mid x$ is a factrr of  36}


Question 5

i) {0,4,8 ,8,12,16}; {whole numbers which are divisible by 4 and less than 20}

ii) {1,4,9,16,25,36,49};{square of first seven natural number}

iii) {-1,1,3,5,7};{odd integers which lie between -2 and 8}

iv) {U,L,T,I,M,A};{letters in the word ULTIMATUM}

Question 6

i) $\{5,6,7,8,9\}$

ii) $\{-12,-6,0,6,12\}$

iii) $\{0,3,8,15\}$

iv) $\{1\}$

V) $\{N, T\}$

vi) $\{1,0,5,6,7\}$

Question 7

i) {x:x is an odd natural number and $x<30$}

ii) {$x \mid x$ is a prime number and $x<30$}

iii) $\left\{x \mid x=n^{2}, n \in N\right\}$

iv) $\left\{x \mid x=\frac{1}{n}, \quad \eta \in N\right.$ and $\left.5 \leq n \leq 20\right\}$

v) $\{x \mid x=s p, p \in I$ and $-2 \leq p \leq 5\}$

vi) $\{x: x$ is a month of a year whose name beings with letter 'J'


Question 8

i) {Vowels in the word COMPETITION}

ii) {x: x is a vowel in the word COMPETITION}

iii) {O,E,I}


EXERCISE:5.2


Question 1

i) Finite set having seven colours

ii)Empty set , having no element in between 

iii) Infinite set , having infinite elements 

iv) Infinite set 

v) Finite set, Having finite digits i.e 6

vi)Finite set, having 6 letters 

vii)Infinite Set , have infinite numbers 

viii)Finite set , have 8 prime factors

ix) Empty set, have no vowel in the word

x)Finite set , 12 element in it .


Question 2

(i),(ii),(iii),(iv) represent same sets 

(iv) is different from other sets

Question 3

A, B and E are equal 

C,F and H are equal 

D and G are equal 


Question 4

A, C , E and G are equivalent , These are having 7 elements 

B and D are equivalent , having 3 element 

F and H are equivalent , having 12 element 

I and J are equivalent , having 52 elements

Question 5

i) $A \subset B, B C A, A=B$

ii) $A \subset B$ but $B \& A$

iii) $B  \subset A$ but $A \subset B$

iv) neither $A \subset B$ nor $B \subset A$

Question 6

i) False

ii) False

iii) True, because there are 5 elements in each


Question 7

i) $\phi$

ii) $\phi,\{3\},\{5\},\{3,5\}$

iii) $\phi,\{2\},\{4\},\{6\},\{2,4\},\{4,6\},\{2,6\}$,{2,4,6}

Question 8

i) $\xi=N$

$A=\{2,4,6,8\}$

ii) $\quad \xi=W$

$A=\{0,2,4,6,8\}$

iii) $\xi=d$

$A=\{\ldots,-4,-2,0,2,4,6,8\}$
















































































































































































































































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