Question:
${ }^{71} \mathrm{C}_{71}$
Solution:
We know that:
${ }^{\mathrm{n}} \mathrm{C}_{\mathrm{r}}=\frac{n !}{(n-r) ! \times r !}$
$\Rightarrow{ }^{71} \mathrm{C}_{71}=\frac{71 !}{(71-71) ! \times 71 !}$
$\Rightarrow{ }^{71} C_{71}=\frac{1}{0 !}$
$\Rightarrow{ }^{71} \mathrm{C}_{71}=\frac{1}{1} \ldots(0 !=1)$
$\Rightarrow{ }^{71} \mathrm{C}_{71}=1$
Ans: ${ }^{71} \mathrm{C}_{71}=1$