If A = {3, 6, 9, 12, 15} and B = {6, 12, 18}, what is A − B?
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Answer and explanation
Correct answer: {3, 9, 15}
The difference A − B contains elements of the first set A that are not present in the second set B. Starting with A = {3, 6, 9, 12, 15}, remove 6 and 12 because they belong to B. The elements 3, 9, and 15 remain; 18 is not in A and therefore cannot be included. Thus A − B = {3, 9, 15}.
Frequently asked questions
What is the correct answer to this question?
{3, 9, 15}
Why is this the correct answer?
The difference A − B contains elements of the first set A that are not present in the second set B. Starting with A = {3, 6, 9, 12, 15}, remove 6 and 12 because they belong to B. The elements 3, 9, and 15 remain; 18 is not in A and therefore cannot be included. Thus A − B = {3, 9, 15}.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
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