NCTB Class 8 Math Chapter Seven Exercise 7 Solutions by Math Expert. Bangladesh Board Class 8 Math Solution Chapter Seven Set Exercise 7 Solution.
|
Board |
NCTB |
| Class |
8 |
|
Subject |
Mathematics |
| Chapter |
7 |
|
Chapter Name |
Set |
| Exercise |
7 Solution |
Exercise 7
1> How many systems are there to express set ?
Ans : (B) 2 system
2> which one of the following is the subset of any set ?
Ans: (b)
3> how many elements are there in the set ?
Ans: (B)
4> S= {X:X even number and 1≤X≤7} which one of the following is correct in tabular set system ?
Ans: (b) {2,4,6}
5> Express the following sets in tabular form:
(a) x={5,7,11,13}
(b) x={2,3}
(c) x={3,6,9,12,15,18,21,24,27,30,33}
(d)x={-3,-2,-1,0,1,2,3}
6> Express the following sets in set builder form :
Ans:
(a) {x:x is natural number and 2<x<9}
(b) {x:x multiple of 4 and x<28}
(c) {x:x is a prime number and 5<x<19}
7> Find the subsets and the number of subsets of the following two sets :
Ans: (a) C={m,n}
Therefore, {m,n} {m},{n}, 4 subset.
(b) D= {5,10,15}
Subsets are: {5,10,15},{5,10},{5,15}{10,15}
{5}{10}{15}; 8 subsets.
8> If A- (2, 3, 4) and B- (5, 7), which one will be A͡ B?
Ans: (b) {0} Ans.
9> Which one is the tabular form of A=(x:x is even number and 4<x<6)
Ans: (d)
10> If P (x, y,z}, which one of the following is not subset of P ?
Ans: (b) {x,w,z}
- What is the set of factors of 10 ?
(a) (1, 2, 5,10) (b) (1, 10} (c) {10) (d) (10, 20, 30}
Ans: (a) {1,2,5,10}
12> If A= (1,2,3), B= (2, a) and C= (a, b), find the following sets:
Ans: (a) = {1,2,3,a}
(b) {a}
(c) {2}
(d) = {1,2,3,a,b}
(e) = {2,a}
14> If P and Q are the sets of all the factors of 21 and 35 respectively, find PUQ.
Ans: {1,3,5,7,21,35}
15> If, A = (2, 3, 5}
Ans: (D) 1,2,3 are correct.
16> Which one is Ac ?
Ans: (c) {3,7}
17> Ans: (b) {5}
18>
Which one is universal set ?
Ans: (d)
19> Which one is the set Bc ?
Ans: (c) {1,4,7,8}
20> Ans: {1,4,2,3}∩{5,6,2,3}
= {1,4}
21> AUb= {1,4,2,3}U{5,6,2,3}
= (a) {1,2,3,4,5,6} Ans:
22> In a hostel, 65% of the students like fish, 55% of the students like meat and 40% of the students like both.
(a) Express the stated information by Venn diagram with short explanation.
(b) Find out the percentage of students who dislike both dishes.
(c) Find out the intersection set of the sets of factors of those students, who like only one dish.
Ans:
