Evaluate 11P4?

1 Answer
May 1, 2018

=11*10*9*8 which equals to:
7920

Explanation:

The formula for permutations is:
P(n,r)=(n!)/((n−r))! or in this form
=_nP_r=(n!)/((n−r)!). Using the givens we know:
n=11 and r=4. Inputting values:
=_(11)P_4=(11!)/((11−4)!) Simplifying:
=_(11)P_4=(11!)/(7!) Since 7! =7*6*5... and 11! =11*10...*7*6*5... we can cancel out the factors from 7 on down to get:
=11*10*9*8 which equals to:
7920
Source (I forgot equation)