If U = {1, 2, 3, 4, 5, 6, 7} and A = {2, 3, 5, 7}, how many elements of A' are less than 4?
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Answer and explanation
Correct answer: 1
The complement is taken with respect to U. Removing the elements of A from U gives A' = U − A = {1, 4, 6}. Among these elements, only 1 is strictly less than 4; the number 4 itself is not less than 4. Therefore, exactly one element satisfies the condition, so option A is correct.
Frequently asked questions
What is the correct answer to this question?
1
Why is this the correct answer?
The complement is taken with respect to U. Removing the elements of A from U gives A' = U − A = {1, 4, 6}. Among these elements, only 1 is strictly less than 4; the number 4 itself is not less than 4. Therefore, exactly one element satisfies the condition, so option A is correct.
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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