JEE Main 2026 Mathematics question

MathematicsSets and RelationJEE Main 2026

Let A = {2, 3, 4, 5, 6}. Let R be a relation on the set A × A given by (x, y)R(z, w) if and only if x divides z and y ≤ w. Then the number of elements in R is .

Answer: 120

Solution

The count factorises: (number of pairs with x|z) × (number of pairs with y ≤ w) = 8 × 15 = 120.

Question ID VK-015130