If A = {1, 2}, B = {1, 2, 2}, and C = {2, 1}, which statement is correct?
Answer and explanation
Correct answer: A = B = C
In set notation, repetition of an element does not create a new element, and the order in which elements are written does not matter. Thus, B = {1, 2, 2} is the same set as {1, 2}, because the repeated 2 is counted only once. Also, C = {2, 1} has exactly the same elements as A, only in a different order. Therefore, A = B = C, so option C is correct.
Frequently asked questions
What is the correct answer to this question?
A = B = C
Why is this the correct answer?
In set notation, repetition of an element does not create a new element, and the order in which elements are written does not matter. Thus, B = {1, 2, 2} is the same set as {1, 2}, because the repeated 2 is counted only once. Also, C = {2, 1} has exactly the same elements as A, only in a different order. Therefore, A = B = C, so option C is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.
