If A = {x : x is a prime number and 10 < x < 30}, which set is obtained in roster form?
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Answer and explanation
Correct answer: A = {11, 13, 17, 19, 23, 29}
The strict inequalities require numbers greater than 10 and less than 30, so 10 and 30 are excluded. Checking the integers in that interval, the prime numbers are 11, 13, 17, 19, 23, and 29. Numbers such as 12, 15, and 21 are composite, so they cannot be included.
Frequently asked questions
What is the correct answer to this question?
A = {11, 13, 17, 19, 23, 29}
Why is this the correct answer?
The strict inequalities require numbers greater than 10 and less than 30, so 10 and 30 are excluded. Checking the integers in that interval, the prime numbers are 11, 13, 17, 19, 23, and 29. Numbers such as 12, 15, and 21 are composite, so they cannot be included.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
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