If U = {red, blue, green} and A = {red}, what is A', the complement of A in U?
Answer and explanation
Correct answer: {blue, green}
The complement A' is defined relative to the universal set U: A' = U \ A. It contains every element of U that is not an element of A. Starting with U = {red, blue, green} and removing red, which is the only element of A, leaves {blue, green}. Therefore A' = {blue, green}, so option B is correct. The other options either give A itself, an incomplete set, or an empty set.
Frequently asked questions
What is the correct answer to this question?
{blue, green}
Why is this the correct answer?
The complement A' is defined relative to the universal set U: A' = U \ A. It contains every element of U that is not an element of A. Starting with U = {red, blue, green} and removing red, which is the only element of A, leaves {blue, green}. Therefore A' = {blue, green}, so option B is correct. The other options either give A itself, an incomplete set, or an empty set.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Complement of a Set and Its Properties.
