If U = {1,2,3,4,5,6,7,8,9,10,11,12} and A = {2,3,5,7,11}, what is the correct description of A′?
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Answer and explanation
Correct answer: 1 and composite numbers in U
The set A contains all prime numbers from 1 through 12: 2,3,5,7, and 11. The complement therefore contains every element of U that is not prime. Number 1 is neither prime nor composite, while 4,6,8,9,10, and 12 are composite. Hence A′ is {1,4,6,8,9,10,12}, described by option A.
Frequently asked questions
What is the correct answer to this question?
1 and composite numbers in U
Why is this the correct answer?
The set A contains all prime numbers from 1 through 12: 2,3,5,7, and 11. The complement therefore contains every element of U that is not prime. Number 1 is neither prime nor composite, while 4,6,8,9,10, and 12 are composite. Hence A′ is {1,4,6,8,9,10,12}, described by option A.
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.
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