^nC_r= \frac{^nP_r}{r!}

^nC_2= \frac{n(n-1)}{2}

^nC_r= \frac{^nP_r}{r!}

^nC_2= \frac{n(n-1)}{2}

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That’s right and awesome

Thanks

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Welcome

Okay

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Bro, it is very easy fact of bionamal theorem

\fbox{Thanks}

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