Sagot :
20 want to joined the dance competiton but 5 are headed, how many ways can adjucator choose to them?
P=(20,5)
=20!
––––
(20-5)!
=20!
––––
15!
=20·19·18·17·16·15
---------------------------
15
*cancel both 15
P=97,920 ways
20 want to joined the dance competiton but 5 are headed, how many ways can adjucator choose to them?
P=(20,5)
=20!
––––
(20-5)!
=20!
––––
15!
=20·19·18·17·16·15
---------------------------
15
*cancel both 15
P=97,920 ways