If A = {r, s} and B = {r, s, t, u}, what is A ∪ B?
Answer and explanation
Correct answer: {r, s, t, u}
The union of two sets contains every element that belongs to at least one of the sets, without repeating any element. Here A = {r, s} and B = {r, s, t, u}. Since every element of A is already in B, combining the sets gives A ∪ B = {r, s, t, u}. Thus option C is correct. Option A omits t and u, option B omits r and s, and option D incorrectly represents the empty set.
Frequently asked questions
What is the correct answer to this question?
{r, s, t, u}
Why is this the correct answer?
The union of two sets contains every element that belongs to at least one of the sets, without repeating any element. Here A = {r, s} and B = {r, s, t, u}. Since every element of A is already in B, combining the sets gives A ∪ B = {r, s, t, u}. Thus option C is correct. Option A omits t and u, option B omits r and s, and option D incorrectly represents the empty set.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Operations on Sets (Union, Intersection, Difference).
