How do you evaluate $color(white)()^7 P_3$ ?

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Answer 1 · 2016-08-05T11:13:07

$210$

Written as $color(white)()^7P_3 larr" Permutation"$

Standard form $color(white)(.)^nP_r =(n!)/((n-r)!)$ giving

$(7!)/((7-3)!) = (7xx6xx5xxcancel(4!))/(cancel(4!))$

$=210$

How do you evaluate color(white)()^7 P_3color(white)()^7 P_3 ?