Mathematics · 2019
JEE Main · 11 January 2019, Shift 1 · Q69
The value of r for which ^20 C_r^20 C_0+^20 C_r -1^20 C_1+^20 C_r -2^20 C_2+⋯ +^20 C_0^20 C_r is maximum, is:
The value of $\displaystyle r$ for which $\displaystyle { }^{20} \mathrm{C}_r{ }^{20} \mathrm{C}_0+{ }^{20} \mathrm{C}_{\mathrm{r}-1}{ }^{20} \mathrm{C}_1+{ }^{20} \mathrm{C}_{\mathrm{r}-2}{ }^{20} \mathrm{C}_2+\cdots$ $\displaystyle +{ }^{20} \mathrm{C}_0{ }^{20} \mathrm{C}_{\mathrm{r}}$
is maximum, is :
Official answer
(4)
$\displaystyle 20$
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JEE Main 2019 Mathematics question, with the answer from NTA’s final answer key. Where our answers come from.