Easy Level Worksheet
Very Short Answer Questions (1 Mark Each)
(1) Write the set of prime numbers less than 10.
(2) If A = {2, 4, 6}, how many elements does A have?
Correct! Set A has 3 elements: 2, 4, and 6.
(3) Write the cardinal number of the set B = {a, e, i, o, u}.
Perfect! The cardinal number (number of elements) of B is 5.
(4) Write the power set of {a}.
Excellent! Power set includes the empty set and all subsets: {∅, {a}}.
(5) What is the intersection of sets A = {1, 2, 3} and B = {3, 4, 5}?
Correct! A ∩ B contains only the common element 3.
Short Answer Questions (2 Marks Each)
Note: Answer each question with steps and explanation, in 2-3 sentences. Write down the answers on sheet and submit to the school subject teacher.
(1) Write any two methods of representing a set with examples.
(2) If A = {1, 3, 5}, B = {3, 5, 7}, find A ∪ B and A ∩ B. A ∪ B =
Perfect! Union contains all elements, intersection contains common elements only.
(3) If U = {1, 2, 3, 4, 5, 6, 7}, A = {1, 3, 5}, find A′ (complement of A). A′ =
Excellent! A′ contains all elements in U that are not in A.
(4) Write the roster form of the set of vowels in the English alphabet. (
Correct! Roster form lists all elements explicitly.
(5) Find the number of subsets of the set P = {a, b, c}.
Perfect! For n elements, number of subsets =
Long Answer Questions (4 Marks Each)
Note: Answer each question with steps and explanation. Write down the answers on sheet and submit to the school subject teacher.
(1) If A = {1, 2, 3, 4}, B = {3, 4, 5, 6}, and U = {1, 2, 3, 4, 5, 6}, find (i) A ∪ B (ii) A ∩ B (iii) A′ (iv) B′.
A ∪ B = (
Excellent! All operations correctly performed using the universal set U.
(2) Draw a Venn diagram and represent A ∪ B, A ∩ B for A = {x : x is a vowel in "apple"} and B = {x : x is a vowel in "orange"}.
A = (
Perfect! You identified vowels correctly from both words.
(3) Let A = {2, 4, 6, 8}, B = {4, 8, 10}, and C = {6, 10}. Find (i) A ∩ B (ii) A ∩ C (iii) B ∪ C.
A ∩ B = (
Excellent! All set operations performed correctly.
(4) State and explain the associative law for union of sets with an example.
(5) Define the universal set and complement of a set with a suitable example.
Part B: Objective Questions (1 Mark Each)
Choose the correct answer and write the option (a/b/c/d)
(1) The number of subsets of the set {a, b} is
(a) 2 (b) 4 (c) 3 (d) 1
Correct! For 2 elements, number of subsets =
(2) If A = {1, 2}, B = {2, 3}, then A ∪ B =
(a) {1, 2, 3} (b) {2} (c) {1, 3} (d) {1, 2}
Correct! Union contains all elements from both sets: {1, 2, 3}.
(3) The intersection of two disjoint sets is
(a) {0} (b) {1} (c) ∅ (d) Universal set
Correct! Disjoint sets have no common elements, so their intersection is empty.
(4) The power set of a set with 3 elements has
(a) 6 elements (b) 9 elements (c) 8 elements (d) 4 elements
Correct! Power set has
(5) A set which contains no elements is called
(a) Singleton set (b) Null set (c) Finite set (d) Empty set
Correct! Both "null set" and "empty set" are correct terms for a set with no elements.
(6) If A = {x : x is a natural number < 5}, then A =
(a) {1, 2, 3, 4} (b) {0, 1, 2, 3, 4} (c) {1, 2, 3, 4, 5} (d) {2, 3, 4, 5}
Correct! Natural numbers are {1, 2, 3, ...}, so numbers less than 5 are {1, 2, 3, 4}.
(7) Which of the following is a singleton set?
(a) {1} (b) {1, 2} (c) ∅ (d) {0, 1}
Correct! A singleton set contains exactly one element.
(8) A universal set is
(a) The set containing all elements under consideration
(b) An empty set
(c) A subset of every set
(d) A finite set
Correct! Universal set contains all elements relevant to the problem context.
(9) The union of a set with an empty set is
(a) Empty set (b) Original set (c) Universal set (d) None
Correct! A ∪ ∅ = A (identity law for union).
(10) If A = {x: x is an even number less than 10}, then A =
(a) {2, 4, 6} (b) {2, 4, 6, 8} (c) {1, 2, 3, 4} (d) {4, 6, 8, 10}
Correct! Even numbers less than 10 are {2, 4, 6, 8}.
Sets Challenge
Determine whether these statements about sets are True or False: