Question

If n(A) = 0 then n(P(P(P(A)))) equals​

Answer 1

Answer:

(n−1P5nP5)=(23)(((n−1−5)!(n−1)!)((n−5)!n!))=(23)((n−1)!(n−5)!n!(n−6)!)=(23)((n−1)!⋅(n−5)(n−6)!n(n−1)!⋅(n−6)!)=(23)2x=3(x−5)2x=3x−15∴n=15