diketahui permutasi n + 1 p4 = 6(np3) , nilai n adalah

(n+1) P4=6 nP3
(n+1)!/(n+1-4)!=6 n!/(n-3)!
(n+1)n(n-1)(n-2)(n-3)!/(n-3)!=
6 n(n-1)(n-2)(n-3)!/(n-3)!
(n+1)=6
n=6-1
n=5