Which option correctly represents P = {3, 6, 9, 12, ..., 30}?
Answer and explanation
Correct answer: P = {3n : n ∈ N, 1 ≤ n ≤ 10}
Every member of P is a positive multiple of 3, so it can be written as 3n, where n is natural. The first term 3 corresponds to n = 1, and the last term 30 corresponds to n = 10 because 30 = 3 × 10. Thus n ranges from 1 through 10, giving P = {3n : n ∈ N, 1 ≤ n ≤ 10}. Option D stops at 27 and omits 30.
Frequently asked questions
What is the correct answer to this question?
P = {3n : n ∈ N, 1 ≤ n ≤ 10}
Why is this the correct answer?
Every member of P is a positive multiple of 3, so it can be written as 3n, where n is natural. The first term 3 corresponds to n = 1, and the last term 30 corresponds to n = 10 because 30 = 3 × 10. Thus n ranges from 1 through 10, giving P = {3n : n ∈ N, 1 ≤ n ≤ 10}. Option D stops at 27 and omits 30.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
