alleryStart learning →If A = {1, 2, 3} and B = {3, 4}, find A ∪ B.
- {2, 3, 4}
- {1, 2, 3}
- {1, 2, 4}
- {1, 2, 3, 4}
Show answer and solution
Correct answer: D. {1, 2, 3, 4}
A union B contains every element in either set, with 3 listed only once.
ICSE Class 8 Sets — practice questions
Explore 38 free Sets questions in ICSE Class 8 Mathematics. Open each question or exercise to read its content, reference answers and available explanation.
Practise Sets with Quill →Sets questions and exercises with answers
Showing questions 1–30 of 38.
If A = {1, 2, 3} and B = {3, 4}, find A ∪ B.Read the answer and worked solution →Which elements occur in both {1, 2, 3, 4} and {3, 4, 5, 6}?Read the answer and worked solution →Which pair of sets is disjoint?Read the answer and worked solution →For A ⊆ U, taking its union with the empty set ∅ always gives?Read the answer and worked solution →A ⊆ U. What remains common to A and the empty set ∅?Read the answer and worked solution →A ⊆ U. Repeating A in the union A ∪ A produces which set?Read the answer and worked solution →For A ⊆ U, intersecting A with itself always gives which set?Read the answer and worked solution →A is contained in universal set U. Which set is A ∪ U?Read the answer and worked solution →Which set consists of the elements common to U and its subset A?Read the answer and worked solution →U = {1, 2, 3, 4, 5, 6} and A = {2, 4, 6}. Find A′ in U.Read the answer and worked solution →A ⊆ U. Both complements use U. What is (A′)′?Read the answer and worked solution →A and its complement A′ use the same universe U. Find A ∪ A′.Read the answer and worked solution →How many elements can belong to both A and its complement in the same universe?Read the answer and worked solution →Reverse the order of two sets. Which result can change?Read the answer and worked solution →A lists chess-club members and B lists music-club members. Which set lists students in both clubs?Read the answer and worked solution →U has 20 elements and A ⊆ U has 12. How many elements are in A′?Read the answer and worked solution →Disjoint sets A and B have 5 and 7 elements. How many elements are in A ∪ B?Read the answer and worked solution →x belongs to B but not A. Adding x to A changes the number of elements in A ∪ B how?Read the answer and worked solution →If A ∩ B = A, which equality must follow?Read the answer and worked solution →For arbitrary sets A and B, simplify A ∪ (A ∩ B) and A ∩ (A ∪ B), in that order.Read the answer and worked solution →In U = {1, 2, 3, 4}, take A = {1} and B = {2}. Which description is correct?Read the answer and worked solution →A = {1}. Its universe changes from {1, 2} to {1, 2, 3}. What happens to A′?Read the answer and worked solution →A = {1, 2, 3}, B = {3, 4}. Which set contains elements in exactly one of A and B?Read the answer and worked solution →U = {1, 2, 3, 4, 5, 6}, A = {1, 2}, B = {2, 3}. Which elements lie in neither A nor B?Read the answer and worked solution →Among 30 students, 12 play chess, 10 play tennis and 4 play both. How many play at least one?Read the answer and worked solution →18 pupils study music, 14 study art and 6 study both. How many study music but not art?Read the answer and worked solution →16 pupils play chess, 11 sing and 5 do both. How many do exactly one of these activities?Read the answer and worked solution →Of 25 pupils, 12 cycle, 10 swim and 4 do both. How many do neither activity?Read the answer and worked solution →Which triple has A ∩ B = B ∩ C = ∅ but A ∩ C ≠ ∅?Read the answer and worked solution →A = {1, 2}, B = {2, 3}, C = {1, 3}. Find (A ∪ B) ∩ C.Read the answer and worked solution →
Worked practice questions
Which elements occur in both {1, 2, 3, 4} and {3, 4, 5, 6}?
- {5, 6}
- {2, 5}
- {1, 2}
- {3, 4}
Show answer and solution
Correct answer: D. {3, 4}
Only 3 and 4 belong to both sets.
Which pair of sets is disjoint?
- {1, 2} and {3, 4}
- {1, 2} and {2, 3}
- {1, 3} and {3, 4}
- {2, 4} and {1, 4}
Show answer and solution
Correct answer: A. {1, 2} and {3, 4}
The sets {1, 2} and {3, 4} have no common element.
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