If A = [−5, −1), which number is not in A?
Answer and explanation
Correct answer: −1
The interval [−5, −1) includes −5 because the left square bracket means the left endpoint is included. It contains every number greater than −5 and less than −1. The right round bracket means −1 itself is excluded. Thus −3 and −4.5 are inside the interval, −5 is included, and −1 is the only number that is not in A. Therefore option C is correct.
Frequently asked questions
What is the correct answer to this question?
−1
Why is this the correct answer?
The interval [−5, −1) includes −5 because the left square bracket means the left endpoint is included. It contains every number greater than −5 and less than −1. The right round bracket means −1 itself is excluded. Thus −3 and −4.5 are inside the interval, −5 is included, and −1 is the only number that is not in A. Therefore option C is correct.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: The Empty Set, Finite and Infinite Sets, Equal Sets.
