How do you evaluate 5P4?
1 Answer
Jan 17, 2018
Explanation:
#"using the definition for "^nP_r#
#•color(white)(x)^nP_r=(n!)/((n-r)!)#
#"where "n! =n(n-1)(n-2)...... xx3xx2xx1#
#rArr^5P_4=(5!)/((5-4)!)=(5!)/(1!)#
#[1! =1]#
#rArr^5P_4=5! =5xx4xx3xx2xx1=120#
