Which option writes A = {x : x ∈ ℝ and x > 7} in interval notation?
Answer and explanation
Correct answer: (7, ∞)
The condition x > 7 includes all real numbers greater than 7 but excludes 7 itself. Exclusion of a finite endpoint is shown by a round parenthesis, so the interval is (7, ∞). Infinity is never an actual endpoint and is always written with a round parenthesis. The other choices either include 7 or describe numbers less than 7.
Frequently asked questions
What is the correct answer to this question?
(7, ∞)
Why is this the correct answer?
The condition x > 7 includes all real numbers greater than 7 but excludes 7 itself. Exclusion of a finite endpoint is shown by a round parenthesis, so the interval is (7, ∞). Infinity is never an actual endpoint and is always written with a round parenthesis. The other choices either include 7 or describe numbers less than 7.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Sets and their representations.
