p-n-find-A-n-p-A-n-1-p-

Question Number 163443 by henderson last updated on 07/Jan/22

p ⩽ n

find \frac{A_{n}^{p}}{A_{n - 1}^{p}} .

Commented by mr W last updated on 07/Jan/22

w h a t i s A_{n} ?

Commented by greg_ed last updated on 07/Jan/22

Arrangement \dots

Commented by mr W last updated on 07/Jan/22

A_{n}^{p} = C_{n}^{p} o r = P_{n}^{p}

Commented by Ar Brandon last updated on 07/Jan/22

P_{n}^{p} in the French way, Sir .

Commented by mr W last updated on 07/Jan/22

t h a n k s!

Commented by mr W last updated on 07/Jan/22

A_{n}^{p} = \frac{n!}{(n - p)!}

A_{n - 1}^{p} = \frac{(n - 1)!}{(n - 1 - p)!}

\frac{A_{n}^{p}}{A_{n - 1}^{p}} = \frac{n!}{(n - p)!} \times \frac{(n - 1 - p)!}{(n - 1)!} = \frac{n}{n - p}

Commented by henderson last updated on 10/Jan/22

cool!