If {x, 5} = {3, y}, which pair can be correct?
Answer and explanation
Correct answer: x = 3, y = 5
Two sets are equal only when they contain exactly the same elements, regardless of the order in which those elements are written. The left-hand set already contains 5, so the right-hand set must also contain 5; this requires y = 5. The right-hand set contains 3, so the left-hand set must contain 3; this requires x = 3. Therefore option A gives {3,5} = {3,5}. Each other pair produces unequal sets or a repeated element on one side.
Frequently asked questions
What is the correct answer to this question?
x = 3, y = 5
Why is this the correct answer?
Two sets are equal only when they contain exactly the same elements, regardless of the order in which those elements are written. The left-hand set already contains 5, so the right-hand set must also contain 5; this requires y = 5. The right-hand set contains 3, so the left-hand set must contain 3; this requires x = 3. Therefore option A gives {3,5} = {3,5}. Each other pair produces unequal sets or a repeated element on one side.
Which subject and chapter does this question cover?
This is a Class 10 Mathematics question. Chapter: Sets. Topic: Equal sets and Subsets.
