1. If A = { a, b, c, d, e }, B = { c, d, e, f }, C = { b, d }, D = { a, e } then which of the following statements are true and which are false?

  1. C ⊆ B
  2. A ⊆ D
  3. D ⊆ B
  4. D ⊆ A
  5. B ⊆ A
  6. C ⊆ A
Solution:
  1. C ⊆ B: False
  2. A ⊆ D: False
  3. D ⊆ B: False
  4. D ⊆ A: True
  5. B ⊆ A: False
  6. C ⊆ A: True

2. Take the set of natural numbers from 1 to 20 as a universal set and show set X and Y using Venn Diagram.
  1. X = { x | x ∈ N, and 7 < x < 15 }
  2. Y = { y | y ∈ N, y is a prime number from 1 to 20 }
Solution:

First, let's write the given sets in the list form:

U = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
X = {8, 9, 10, 11, 12, 13, 14}
Y = {2, 3, 5, 7, 11, 13, 17, 19}

The completed Venn Diagram is given below:

Practice Set 1.3 : Problem 2 : Textbook Page 11


3. U = { 1, 2, 3, 7, 8, 9, 10, 11, 12} P = { 1, 3, 7, 10 } then,
(i) show the sets U, P and P' by Venn Diagram
(ii) Verify (P')' = P
Solution:
Practice Set 1.3 : Problem 3 : Textbook Page 11

Now, P' = { 2, 8, 9, 11, 12 }

and (P')' = { 1, 3, 7, 10 }

∴ (P')' = P


4. A = { 1, 3, 2, 7 } then write any three subsets of A.
Solution:

All the subsets of A are given below. You can write any three:

  • {1}
  • {2}
  • {3}
  • {7}
  • {1, 2}
  • {1, 3}
  • {1, 7}
  • {2, 3}
  • {2, 7}
  • {3, 7}
  • {1, 2, 3}
  • {1, 2, 7}
  • {1, 3, 7}
  • {2, 3, 7}
  • {1, 2, 3, 7}
  • φ


5 (i) Write the subset relation between the sets:
  • P is the set of all residents in Pune
  • M is the set of all residents in Madhya Pradesh
  • I is the set of all residents in Indore
  • B is the set of all residents in India
  • H is the set of all residents in Maharashtra
Solution:

The subset relations are as follows:

  • P ⊆ H
  • P ⊆ B
  • I ⊆ M
  • I ⊆ B
  • H ⊆ B
  • M ⊆ B

Now, every set is a subset of itself:

  • P ⊆ P
  • M ⊆ M
  • I ⊆ I
  • B ⊆ B
  • H ⊆ H

Also, an empty set is a subset of every set:

  • φ ⊆ P
  • φ ⊆ M
  • φ ⊆ I
  • φ ⊆ B
  • φ ⊆ H
5 (ii) Which set can be the universal set for the above sets?
Solution:

The set of all residents in India (B), can be the universal set for the above sets.


6 (i): Which set of numbers could be the universal set for the sets given below?
  • A = the set of multiples of 5
  • B = the set of multiples of 7
  • C = the set of multiples of 12
Solution:

Set N, Set W, Set I
(You can write any one of them)

6 (ii): P = the set of integers which are multiples of 4, T = the set of all even square numbers
Solution:

Set N, Set W, Set I
(You can write any one of them)


7. Let, all the students of a class be the Universal set. Let, set A be the students who secure 50% or more marks in Maths.
Then write the complement of set A.
Solution:

The set of students getting less than 50% marks in Maths.




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17 April 2026 at 10:45

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