JEE Mains · Maths · STD 12 - 1. relation and function
Let \( A=\{2,3,5,7,9\} \). Let R be the relation on A defined by \(x\) Ry if and only if \( 2x\le3y \). Let \(l\) be the number of elements in R, and m be the minimum number of elements required to be added in R to make it a symmetric relation. Then \( l+m \) is equal to :
- A 23
- B 25
- C 21
- D 27
Answer & Solution
Correct Answer
(B) 25
Step-by-step Solution
Detailed explanation
\( A=\{2,3,5,7,9\} \) \( y\ge\frac{2x}{3} \) \(\left.\begin{array}{ll}x=2, & y=2,3,5,7,9 \\ x=3, & y=2,3,5,7,9 \\ x=5, & y=5,7,9 \\ x=7, & y=5,7,9 \\ x=9 & y=7,9\end{array}\right] \rightarrow \ell=18\) to make it symmetric elements to be added are {(5,2), (7,2), (9,2),…
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