JEE Mains · Maths · STD 12 - 1. relation and function
Let \(A=\{1,3,4,6,9\}\) and \(B=\{2,4,5,8,10\}\). Let \(R\) be a relation defined on \(A \times B\) such that \(R =\) \(\left\{\left(\left(a_1, b_1\right),\left(a_2, b_2\right)\right): a_1 \leq b_2\right.\) and \(\left.b_1 \leq a_2\right\}\). Then the number of elements in the set \(R\) is
- A \(26\)
- B \(160\)
- C \(180\)
- D \(52\)
Answer & Solution
Correct Answer
(B) \(160\)
Step-by-step Solution
Detailed explanation
Let \(a_1=1 \Rightarrow 5\) choices of \(b _2\) \(a_1=3 \Rightarrow 4 \text { choices of } b_2\) \(a_1=4 \Rightarrow 4 \text { choices of } b_2\) \(a_1=6 \Rightarrow 2 \text { choices of } b_2\) \(a_1=9 \Rightarrow 1 \text { choices of } b_2\) For \(\left(a_1, b _2\right) 16\)…
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