1. Which of the following is a valid element of the set { 1, 2, 3, 4 }?
Solution
Correct: B
The elements listed in the set are 1, 2, 3, and 4. Therefore, 3 is correct.
2. Which of the following represents the set of even numbers less than 10 using the roster method?
Solution
Correct: B
Even numbers less than 10 are 2, 4, 6, and 8. These must all be included in the roster.
3. The set-builder form of the set { 3, 4, 5 } is:
Solution
Correct: B
Natural numbers between 2 and 5 are 3, 4, and 5, matching the given set.
4. Which of the following sets is a subset of { a, b, c }?
Solution
Correct: B
A subset must contain elements that are all in the original set. { b } is a subset.
5. The union of { 1, 2, 3 } and { 2, 3, 4 } is:
Solution
Correct: A
Union combines all unique elements from both sets, including 1, 2, 3, 4.
6. The intersection of { a, b, c } and { c, d, e } is:
Solution
Correct: A
Intersection includes elements common to both sets; only 'c' is common.
7. The difference between sets A = { 1, 2, 3, 4 } and B = { 3, 4, 5 } is:
Solution
Correct: A
The difference A - B includes elements in A not in B; 1 and 2 remain.
8. Which set represents all vowels in the English alphabet?
Solution
Correct: A
The vowels in English are a, e, i, o, and u. All must be included.
9. Which of the following is an empty set?
Solution
Correct: A
An empty set has no elements. The notation { } represents it.
10. How many elements are in the set { x | x is a prime number less than 10 }?
Solution
Correct: A
Prime numbers less than 10 are 2, 3, 5, and 7. Total = 4.
11. Which set is finite?
Solution
Correct: B
Days in a week are countable (7), making this set finite.
Discussion & Comments