JEE Mains · Maths · STD 12 - 1. relation and function
Let \(A =\{2,3,4\}\) and \(B =\{8,9,12\}\). Then the number of elements in the relation \(R=\left\{\left(\left(a_1, b_1\right),\left(a_2, b_2\right)\right) \in(A \times B, A \times B): a_1\right.\) divides \(b_2\) and \(a_2\) divides \(\left.b_1\right\}\) is:
- A \(36\)
- B \(12\)
- C \(18\)
- D \(24\)
Answer & Solution
Correct Answer
(A) \(36\)
Step-by-step Solution
Detailed explanation
\(a_1\) divides \(b_2\) Each element has 2 choices \(\Rightarrow 3 \times 2=6\) \(a_2\) divides \(b_1\) Each element has \(2\) choices \(\Rightarrow 3 \times 2=6\) \(\text { Total }=6 \times 6=36\)
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