If P = {x : x is a perfect square and x < 20}, what is its roster form?
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Answer and explanation
Correct answer: P = {1, 4, 9, 16}
The positive perfect squares below 20 are 1² = 1, 2² = 4, 3² = 9, and 4² = 16. The next square, 5² = 25, is not below 20. Therefore the roster form is {1, 4, 9, 16}, making option A correct.
Frequently asked questions
What is the correct answer to this question?
P = {1, 4, 9, 16}
Why is this the correct answer?
The positive perfect squares below 20 are 1² = 1, 2² = 4, 3² = 9, and 4² = 16. The next square, 5² = 25, is not below 20. Therefore the roster form is {1, 4, 9, 16}, making option A correct.
Which subject and chapter does this question cover?
This is a Class 9 Mathematics question. Chapter: Common Questions. Topic: General chapter practice.
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