Mathematics · 2021
JEE Main · 16 March 2021, Shift 2 · Q71
Let A ={2,3,4,5, …, 30} and ' ≃ ' be an equivalence relation on A × A, defined by ( a, b ) ≃( c, d ), if and only if ad = bc. Then the number of…
Let $\displaystyle \mathrm{A}=\{2,3,4,5, \ldots, 30\}$ and ' $\displaystyle \simeq$ ' be an equivalence relation on $\displaystyle \mathrm{A} \times \mathrm{A}$, defined by $\displaystyle (\mathrm{a}, \mathrm{b}) \simeq(\mathrm{c}, \mathrm{d})$, if and only if $\displaystyle \mathrm{ad}=\mathrm{bc}$. Then the number of ordered pairs which satisfy this equivalence relation with ordered pair $\displaystyle (4,3)$ is equal to :
Official answer
(3)
$\displaystyle 7$
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JEE Main 2021 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.