1. Which of the following is not a set?
Answer:
Explanation:
"Interesting numbers" is a subjective term and not well-defined, so it's not a set.
2. A set with no elements is called:
Answer:
Explanation:
A set with no elements is called a null set or empty set.
3. If A = {x: x is an even number less than 10}, then A is:
Answer:
Explanation:
The set A contains even numbers less than 10.
4. The set of all letters in the word "LETTER" is:
Answer:
Explanation:
In set theory, repetitive elements are counted once.
5. The number of subsets of the set {1, 2, 3} is:
Answer:
Explanation:
The subsets are {}, {1}, {2}, {3}, {1,2}, {1,3}, {2,3}, {1,2,3}.
6. The universal set is denoted by:
Answer:
Explanation:
The universal set, which often contains all the elements under consideration, is denoted by U.
7. If A = {1, 2, 3} and B = {3, 4, 5}, A ∩ B is:
Answer:
Explanation:
A ∩ B represents the intersection of sets A and B, which is the set of common elements.
8. The set {x: x is a prime number less than 10} is:
Answer:
Explanation:
Prime numbers less than 10 are 2, 3, 5, and 7.
9. Two sets with no common elements are called:
Answer:
Explanation:
Sets with no common elements are termed as disjoint sets.
10. If A = {1, 2} and B = {3, 4}, the Cartesian product A x B is:
Answer:
Explanation:
The Cartesian product A x B is the set of all ordered pairs (a,b) where a is in A and b is in B.
11. A set that contains an infinite number of elements is called:
Answer:
Explanation:
An infinite set has an endless number of elements.
12. If A = {x: x is a natural number less than 5}, then A is:
Answer:
Explanation:
The set A contains natural numbers less than 5.
13. The complement of set A with respect to the universal set U is denoted by:
Answer:
Explanation:
The complement of set A with respect to U is the set of all elements in U that are not in A.
14. The set of all real numbers between 1 and 10 is represented by:
Answer:
Explanation:
This represents all real numbers greater than 1 and less than 10.
15. If A = {a, b, c} and B = {b, c, d}, A ∪ B is:
Answer:
Explanation:
A ∪ B represents the union of sets A and B, which includes all unique elements from both sets.
16. If N is the set of natural numbers, then the set {x: x ∈ N, x^2 < 30} is:
Answer:
Explanation:
The numbers 1^2, 2^2, 3^2, and 4^2 are all less than 30, but 5^2 is 25 which is less than 30, however, 6^2 is 36 which is greater than 30.
17. Two sets that contain exactly the same elements are called:
Answer:
Explanation:
Sets that have the same elements are termed as equal sets.
18. The set {x: x is a vowel in the word "APPLICATION"} is:
Answer:
Explanation:
The vowels in the word "APPLICATION" are A and I.
19. If A ⊆ B, it implies:
Answer:
Explanation:
A ⊆ B denotes that every element of set A is also an element of set B.
20. If A = {1, 2, 3} and B = {4, 5}, the number of elements in the Cartesian product A x B is:
Answer:
Explanation:
The Cartesian product A x B will have 3×2 = 6 ordered pairs.