JEE Main 2026 Mathematics question
Let A={1,4,7} and B={2,3,8}. Then the number of elements, in the relation R={((a₁,b₁),(a₂,b₂))∈((A×B)×(A×B)) : a₁+b₂ divides a₂+b₁} is .
Answer: 18
Solution
Direct enumeration over all 81 combinations of (a₁,b₁,a₂,b₂) checking divisibility gives 18.